fix: reverts related changes in #985 that partially allows empty serv…

…ices be generated for sample.

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientHeaderSampleComposer.java

@@ -52,10 +52,6 @@ public static Sample composeClassHeaderSample(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
-    if (service.methods().isEmpty()) {
-      return ServiceClientMethodSampleComposer.composeEmptyServiceSample(clientType, service);
-    }
-
     // Use the first pure unary RPC method's sample code as showcase, if no such method exists, use
     // the first method in the service's methods list.
     Method method =

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/grpcrest/ServiceClientClassComposerTest.java

@@ -40,20 +40,6 @@ void generateServiceClasses() {
     Assert.assertCodeEquals(goldenFilePath, visitor.write());
   }
 
-  @Test
-  void generateServiceClassesEmpty() {
-    GapicContext context = GrpcRestTestProtoLoader.instance().parseShowcaseEcho();
-    Service echoProtoService = context.services().get(1);
-    GapicClass clazz = ServiceClientClassComposer.instance().generate(context, echoProtoService);
-
-    JavaWriterVisitor visitor = new JavaWriterVisitor();
-    clazz.classDefinition().accept(visitor);
-    GoldenFileWriter.saveCodegenToFile(this.getClass(), "EchoEmpty.golden", visitor.write());
-    Path goldenFilePath =
-        Paths.get(GoldenFileWriter.getGoldenDir(this.getClass()), "EchoEmpty.golden");
-    Assert.assertCodeEquals(goldenFilePath, visitor.write());
-  }
-
   @Test
   void generateServiceClassesWicked() {
     GapicContext context = GrpcRestTestProtoLoader.instance().parseShowcaseWicked();