Working on upgrading to latest Java version

.classpath

@@ -13,7 +13,7 @@
 			<attribute name="test" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8">
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-20">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>

.settings/org.eclipse.jdt.core.prefs

@@ -1,9 +1,9 @@
 eclipse.preferences.version=1
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
-org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=20
+org.eclipse.jdt.core.compiler.compliance=20
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
 org.eclipse.jdt.core.compiler.processAnnotations=disabled
-org.eclipse.jdt.core.compiler.release=disabled
-org.eclipse.jdt.core.compiler.source=1.8
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=20

pom.xml

@@ -130,9 +130,9 @@
 
 			<plugin>
 				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.11.0</version>
 				<configuration>
-					<source>1.8</source>
-					<target>1.8</target>
+				  <release>20</release>
 				</configuration>
 			</plugin>
 

src/test/java/delight/nashornsandbox/TestAccessFunction.java

@@ -22,10 +22,6 @@ public void test_access_variable() throws ScriptCPUAbuseException, ScriptExcepti
   }
 
     private Object findAndCall(Object _get) {
-        if (NashornDetection.isJDKNashornScriptObjectMirror(_get)) {
-            jdk.nashorn.api.scripting.ScriptObjectMirror scriptObjectMirror = (jdk.nashorn.api.scripting.ScriptObjectMirror) _get;
-            return scriptObjectMirror.call(_get);
-        }
 
         if (NashornDetection.isStandaloneNashornScriptObjectMirror(_get)) {
             org.openjdk.nashorn.api.scripting.ScriptObjectMirror scriptObjectMirror = (org.openjdk.nashorn.api.scripting.ScriptObjectMirror) _get;