public com.google.protobuf.DescriptorProtos.DescriptorProto.ExtensionRange build() {
          com.google.protobuf.DescriptorProtos.DescriptorProto.ExtensionRange result = buildPartial();
          if (!result.isInitialized()) {
            throw newUninitializedMessageException(result);
          }
          return result;
        }