From 42028ed2b2be47f85b70eb813185264f1f573d01 Mon Sep 17 00:00:00 2001
From: arithmetic1728 <58957152+arithmetic1728@users.noreply.github.com>
Date: Tue, 2 Jun 2020 11:24:04 -0700
Subject: [PATCH] fix: fix python-api-core dependency issue (#931)

`ClientOptions` doesn't have `client_encryted_cert_source` property yet. Check the existence of the property before accessing it.
---
 googleapiclient/discovery.py | 6 +++++-
 setup.py                     | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/googleapiclient/discovery.py b/googleapiclient/discovery.py
index 115609f3e4a..55367c0a491 100644
--- a/googleapiclient/discovery.py
+++ b/googleapiclient/discovery.py
@@ -441,7 +441,11 @@ def build_from_document(
             raise MutualTLSChannelError(
                 "ClientOptions.client_cert_source is not supported, please use ClientOptions.client_encrypted_cert_source."
             )
-        if client_options and client_options.client_encrypted_cert_source:
+        if (
+            client_options
+            and hasattr(client_options, "client_encrypted_cert_source")
+            and client_options.client_encrypted_cert_source
+        ):
             client_cert_to_use = client_options.client_encrypted_cert_source
         elif adc_cert_path and adc_key_path and mtls.has_default_client_cert_source():
             client_cert_to_use = mtls.default_client_encrypted_cert_source(
diff --git a/setup.py b/setup.py
index 8d6edae93d0..f15ae378ea5 100644
--- a/setup.py
+++ b/setup.py
@@ -41,7 +41,7 @@
     "httplib2>=0.9.2,<1dev",
     "google-auth>=1.16.0",
     "google-auth-httplib2>=0.0.3",
-    "google-api-core>=1.13.0,<2dev",
+    "google-api-core>=1.17.0,<2dev",
     "six>=1.6.1,<2dev",
     "uritemplate>=3.0.0,<4dev",
 ]