code: public com.google.protobuf.ByteString
        getMemberBytes() {
      java.lang.Object ref = member_;
      if (ref instanceof java.lang.String) {
        com.google.protobuf.ByteString b = 
            com.google.protobuf.ByteString.copyFromUtf8(
                (java.lang.String) ref);
        member_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
docs: <pre>
  A single identity requesting access for a Cloud Platform resource.
  Follows the same format of Binding.members.
  Required
  </pre>
  
  <code>string member = 3;</code>