private com.google.protobuf.SingleFieldBuilderV3<
            com.google.rpc.Status, com.google.rpc.Status.Builder, com.google.rpc.StatusOrBuilder>
        getResponseStatusFieldBuilder() {
      if (responseStatusBuilder_ == null) {
        responseStatusBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.rpc.Status,
                com.google.rpc.Status.Builder,
                com.google.rpc.StatusOrBuilder>(
                getResponseStatus(), getParentForChildren(), isClean());
        responseStatus_ = null;
      }
      return responseStatusBuilder_;
    }
<pre>
Output only. The response from the target for this attempt.

If the task has not been attempted or the task is currently running
then the response status is unset.
</pre>

<code>.google.rpc.Status response_status = 4;</code>
java-tasks/proto-google-cloud-tasks-v2beta2/src/main/java/com/google/cloud/tasks/v2beta2/AttemptStatus.java