Prevent construction of container classes and reduce API
diff --git a/compiler/src/test/golden/TestServiceNano.java.txt b/compiler/src/test/golden/TestServiceNano.java.txt
index 0af54f2..ea6df13 100644
--- a/compiler/src/test/golden/TestServiceNano.java.txt
+++ b/compiler/src/test/golden/TestServiceNano.java.txt
@@ -18,6 +18,8 @@
 @javax.annotation.Generated("by gRPC proto compiler")
 public class TestServiceGrpc {
 
+  private TestServiceGrpc() {}
+
   public static final String SERVICE_NAME = "grpc.testing.TestService";
 
   // Static method descriptors that strictly reflect the proto.