private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tasks.v2beta3.RetryConfig,
            com.google.cloud.tasks.v2beta3.RetryConfig.Builder,
            com.google.cloud.tasks.v2beta3.RetryConfigOrBuilder>
        getRetryConfigFieldBuilder() {
      if (retryConfigBuilder_ == null) {
        retryConfigBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tasks.v2beta3.RetryConfig,
                com.google.cloud.tasks.v2beta3.RetryConfig.Builder,
                com.google.cloud.tasks.v2beta3.RetryConfigOrBuilder>(
                getRetryConfig(), getParentForChildren(), isClean());
        retryConfig_ = null;
      }
      return retryConfigBuilder_;
    }
<pre>
Settings that determine the retry behavior.

* For tasks created using Cloud Tasks: the queue-level retry settings
  apply to all tasks in the queue that were created using Cloud Tasks.
  Retry settings cannot be set on individual tasks.
* For tasks created using the App Engine SDK: the queue-level retry
  settings apply to all tasks in the queue which do not have retry settings
  explicitly set on the task and were created by the App Engine SDK. See
  [App Engine
  documentation](https://cloud.google.com/appengine/docs/standard/python/taskqueue/push/retrying-tasks).
</pre>

<code>.google.cloud.tasks.v2beta3.RetryConfig retry_config = 5;</code>
java-tasks/proto-google-cloud-tasks-v2beta3/src/main/java/com/google/cloud/tasks/v2beta3/Queue.java