diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsClient.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsClient.java
index dbf1476d..aa88601b 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsClient.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.domains.v1alpha2;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -2053,12 +2052,7 @@ public static ApiFuture<ListRegistrationsPagedResponse> createAsync(
           ListRegistrationsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListRegistrationsPage, ListRegistrationsPagedResponse>() {
-            @Override
-            public ListRegistrationsPagedResponse apply(ListRegistrationsPage input) {
-              return new ListRegistrationsPagedResponse(input);
-            }
-          },
+          input -> new ListRegistrationsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsSettings.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsSettings.java
index ad434f6d..6af9e402 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsSettings.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/DomainsSettings.java
@@ -270,14 +270,13 @@ public DomainsStubSettings.Builder getStubSettingsBuilder() {
       return ((DomainsStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/DomainsStubSettings.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/DomainsStubSettings.java
index 0c21290b..ffd9d74d 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/DomainsStubSettings.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/DomainsStubSettings.java
@@ -846,14 +846,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/GrpcDomainsStub.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/GrpcDomainsStub.java
index e40526dd..23bff2a2 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/GrpcDomainsStub.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1alpha2/stub/GrpcDomainsStub.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.domains.v1alpha2.AuthorizationCode;
 import com.google.cloud.domains.v1alpha2.ConfigureContactSettingsRequest;
@@ -53,7 +52,6 @@
 import io.grpc.MethodDescriptor;
 import io.grpc.protobuf.ProtoUtils;
 import java.io.IOException;
-import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import javax.annotation.Generated;
 
@@ -282,13 +280,10 @@ protected GrpcDomainsStub(
         GrpcCallSettings.<SearchDomainsRequest, SearchDomainsResponse>newBuilder()
             .setMethodDescriptor(searchDomainsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SearchDomainsRequest>() {
-                  @Override
-                  public Map<String, String> extract(SearchDomainsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("location", String.valueOf(request.getLocation()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("location", String.valueOf(request.getLocation()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<RetrieveRegisterParametersRequest, RetrieveRegisterParametersResponse>
@@ -297,27 +292,20 @@ public Map<String, String> extract(SearchDomainsRequest request) {
                 .<RetrieveRegisterParametersRequest, RetrieveRegisterParametersResponse>newBuilder()
                 .setMethodDescriptor(retrieveRegisterParametersMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<RetrieveRegisterParametersRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          RetrieveRegisterParametersRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("location", String.valueOf(request.getLocation()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("location", String.valueOf(request.getLocation()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<RegisterDomainRequest, Operation> registerDomainTransportSettings =
         GrpcCallSettings.<RegisterDomainRequest, Operation>newBuilder()
             .setMethodDescriptor(registerDomainMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<RegisterDomainRequest>() {
-                  @Override
-                  public Map<String, String> extract(RegisterDomainRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListRegistrationsRequest, ListRegistrationsResponse>
@@ -325,40 +313,31 @@ public Map<String, String> extract(RegisterDomainRequest request) {
             GrpcCallSettings.<ListRegistrationsRequest, ListRegistrationsResponse>newBuilder()
                 .setMethodDescriptor(listRegistrationsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListRegistrationsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListRegistrationsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetRegistrationRequest, Registration> getRegistrationTransportSettings =
         GrpcCallSettings.<GetRegistrationRequest, Registration>newBuilder()
             .setMethodDescriptor(getRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateRegistrationRequest, Operation> updateRegistrationTransportSettings =
         GrpcCallSettings.<UpdateRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(updateRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put(
-                        "registration.name", String.valueOf(request.getRegistration().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put(
+                      "registration.name", String.valueOf(request.getRegistration().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ConfigureManagementSettingsRequest, Operation>
@@ -366,27 +345,20 @@ public Map<String, String> extract(UpdateRegistrationRequest request) {
             GrpcCallSettings.<ConfigureManagementSettingsRequest, Operation>newBuilder()
                 .setMethodDescriptor(configureManagementSettingsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ConfigureManagementSettingsRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          ConfigureManagementSettingsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ConfigureDnsSettingsRequest, Operation> configureDnsSettingsTransportSettings =
         GrpcCallSettings.<ConfigureDnsSettingsRequest, Operation>newBuilder()
             .setMethodDescriptor(configureDnsSettingsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ConfigureDnsSettingsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ConfigureDnsSettingsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("registration", String.valueOf(request.getRegistration()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("registration", String.valueOf(request.getRegistration()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ConfigureContactSettingsRequest, Operation>
@@ -394,39 +366,30 @@ public Map<String, String> extract(ConfigureDnsSettingsRequest request) {
             GrpcCallSettings.<ConfigureContactSettingsRequest, Operation>newBuilder()
                 .setMethodDescriptor(configureContactSettingsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ConfigureContactSettingsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ConfigureContactSettingsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ExportRegistrationRequest, Operation> exportRegistrationTransportSettings =
         GrpcCallSettings.<ExportRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(exportRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ExportRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(ExportRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteRegistrationRequest, Operation> deleteRegistrationTransportSettings =
         GrpcCallSettings.<DeleteRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(deleteRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<RetrieveAuthorizationCodeRequest, AuthorizationCode>
@@ -434,13 +397,10 @@ public Map<String, String> extract(DeleteRegistrationRequest request) {
             GrpcCallSettings.<RetrieveAuthorizationCodeRequest, AuthorizationCode>newBuilder()
                 .setMethodDescriptor(retrieveAuthorizationCodeMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<RetrieveAuthorizationCodeRequest>() {
-                      @Override
-                      public Map<String, String> extract(RetrieveAuthorizationCodeRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ResetAuthorizationCodeRequest, AuthorizationCode>
@@ -448,13 +408,10 @@ public Map<String, String> extract(RetrieveAuthorizationCodeRequest request) {
             GrpcCallSettings.<ResetAuthorizationCodeRequest, AuthorizationCode>newBuilder()
                 .setMethodDescriptor(resetAuthorizationCodeMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ResetAuthorizationCodeRequest>() {
-                      @Override
-                      public Map<String, String> extract(ResetAuthorizationCodeRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
 
@@ -694,7 +651,13 @@ public UnaryCallable<DeleteRegistrationRequest, Operation> deleteRegistrationCal
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsClient.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsClient.java
index d91b2516..c84af520 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsClient.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.domains.v1beta1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -2053,12 +2052,7 @@ public static ApiFuture<ListRegistrationsPagedResponse> createAsync(
           ListRegistrationsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListRegistrationsPage, ListRegistrationsPagedResponse>() {
-            @Override
-            public ListRegistrationsPagedResponse apply(ListRegistrationsPage input) {
-              return new ListRegistrationsPagedResponse(input);
-            }
-          },
+          input -> new ListRegistrationsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsSettings.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsSettings.java
index 076fd209..0461621f 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsSettings.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/DomainsSettings.java
@@ -270,14 +270,13 @@ public DomainsStubSettings.Builder getStubSettingsBuilder() {
       return ((DomainsStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/DomainsStubSettings.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/DomainsStubSettings.java
index ca9bc05b..25df33c0 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/DomainsStubSettings.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/DomainsStubSettings.java
@@ -846,14 +846,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/GrpcDomainsStub.java b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/GrpcDomainsStub.java
index 2d808845..b49013c0 100644
--- a/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/GrpcDomainsStub.java
+++ b/google-cloud-domains/src/main/java/com/google/cloud/domains/v1beta1/stub/GrpcDomainsStub.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.domains.v1beta1.AuthorizationCode;
 import com.google.cloud.domains.v1beta1.ConfigureContactSettingsRequest;
@@ -53,7 +52,6 @@
 import io.grpc.MethodDescriptor;
 import io.grpc.protobuf.ProtoUtils;
 import java.io.IOException;
-import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import javax.annotation.Generated;
 
@@ -281,13 +279,10 @@ protected GrpcDomainsStub(
         GrpcCallSettings.<SearchDomainsRequest, SearchDomainsResponse>newBuilder()
             .setMethodDescriptor(searchDomainsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SearchDomainsRequest>() {
-                  @Override
-                  public Map<String, String> extract(SearchDomainsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("location", String.valueOf(request.getLocation()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("location", String.valueOf(request.getLocation()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<RetrieveRegisterParametersRequest, RetrieveRegisterParametersResponse>
@@ -296,27 +291,20 @@ public Map<String, String> extract(SearchDomainsRequest request) {
                 .<RetrieveRegisterParametersRequest, RetrieveRegisterParametersResponse>newBuilder()
                 .setMethodDescriptor(retrieveRegisterParametersMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<RetrieveRegisterParametersRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          RetrieveRegisterParametersRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("location", String.valueOf(request.getLocation()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("location", String.valueOf(request.getLocation()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<RegisterDomainRequest, Operation> registerDomainTransportSettings =
         GrpcCallSettings.<RegisterDomainRequest, Operation>newBuilder()
             .setMethodDescriptor(registerDomainMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<RegisterDomainRequest>() {
-                  @Override
-                  public Map<String, String> extract(RegisterDomainRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListRegistrationsRequest, ListRegistrationsResponse>
@@ -324,40 +312,31 @@ public Map<String, String> extract(RegisterDomainRequest request) {
             GrpcCallSettings.<ListRegistrationsRequest, ListRegistrationsResponse>newBuilder()
                 .setMethodDescriptor(listRegistrationsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListRegistrationsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListRegistrationsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetRegistrationRequest, Registration> getRegistrationTransportSettings =
         GrpcCallSettings.<GetRegistrationRequest, Registration>newBuilder()
             .setMethodDescriptor(getRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateRegistrationRequest, Operation> updateRegistrationTransportSettings =
         GrpcCallSettings.<UpdateRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(updateRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put(
-                        "registration.name", String.valueOf(request.getRegistration().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put(
+                      "registration.name", String.valueOf(request.getRegistration().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ConfigureManagementSettingsRequest, Operation>
@@ -365,27 +344,20 @@ public Map<String, String> extract(UpdateRegistrationRequest request) {
             GrpcCallSettings.<ConfigureManagementSettingsRequest, Operation>newBuilder()
                 .setMethodDescriptor(configureManagementSettingsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ConfigureManagementSettingsRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          ConfigureManagementSettingsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ConfigureDnsSettingsRequest, Operation> configureDnsSettingsTransportSettings =
         GrpcCallSettings.<ConfigureDnsSettingsRequest, Operation>newBuilder()
             .setMethodDescriptor(configureDnsSettingsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ConfigureDnsSettingsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ConfigureDnsSettingsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("registration", String.valueOf(request.getRegistration()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("registration", String.valueOf(request.getRegistration()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ConfigureContactSettingsRequest, Operation>
@@ -393,39 +365,30 @@ public Map<String, String> extract(ConfigureDnsSettingsRequest request) {
             GrpcCallSettings.<ConfigureContactSettingsRequest, Operation>newBuilder()
                 .setMethodDescriptor(configureContactSettingsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ConfigureContactSettingsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ConfigureContactSettingsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ExportRegistrationRequest, Operation> exportRegistrationTransportSettings =
         GrpcCallSettings.<ExportRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(exportRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ExportRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(ExportRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteRegistrationRequest, Operation> deleteRegistrationTransportSettings =
         GrpcCallSettings.<DeleteRegistrationRequest, Operation>newBuilder()
             .setMethodDescriptor(deleteRegistrationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteRegistrationRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteRegistrationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<RetrieveAuthorizationCodeRequest, AuthorizationCode>
@@ -433,13 +396,10 @@ public Map<String, String> extract(DeleteRegistrationRequest request) {
             GrpcCallSettings.<RetrieveAuthorizationCodeRequest, AuthorizationCode>newBuilder()
                 .setMethodDescriptor(retrieveAuthorizationCodeMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<RetrieveAuthorizationCodeRequest>() {
-                      @Override
-                      public Map<String, String> extract(RetrieveAuthorizationCodeRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ResetAuthorizationCodeRequest, AuthorizationCode>
@@ -447,13 +407,10 @@ public Map<String, String> extract(RetrieveAuthorizationCodeRequest request) {
             GrpcCallSettings.<ResetAuthorizationCodeRequest, AuthorizationCode>newBuilder()
                 .setMethodDescriptor(resetAuthorizationCodeMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ResetAuthorizationCodeRequest>() {
-                      @Override
-                      public Map<String, String> extract(ResetAuthorizationCodeRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("registration", String.valueOf(request.getRegistration()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("registration", String.valueOf(request.getRegistration()));
+                      return params.build();
                     })
                 .build();
 
@@ -693,7 +650,13 @@ public UnaryCallable<DeleteRegistrationRequest, Operation> deleteRegistrationCal
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override