private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tasks.v2beta2.PullMessage,
            com.google.cloud.tasks.v2beta2.PullMessage.Builder,
            com.google.cloud.tasks.v2beta2.PullMessageOrBuilder>
        getPullMessageFieldBuilder() {
      if (pullMessageBuilder_ == null) {
        if (!(payloadTypeCase_ == 4)) {
          payloadType_ = com.google.cloud.tasks.v2beta2.PullMessage.getDefaultInstance();
        }
        pullMessageBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tasks.v2beta2.PullMessage,
                com.google.cloud.tasks.v2beta2.PullMessage.Builder,
                com.google.cloud.tasks.v2beta2.PullMessageOrBuilder>(
                (com.google.cloud.tasks.v2beta2.PullMessage) payloadType_,
                getParentForChildren(),
                isClean());
        payloadType_ = null;
      }
      payloadTypeCase_ = 4;
      onChanged();
      return pullMessageBuilder_;
    }
<pre>
[LeaseTasks][google.cloud.tasks.v2beta2.CloudTasks.LeaseTasks] to process
the task. Can be set only if
[pull_target][google.cloud.tasks.v2beta2.Queue.pull_target] is set on the
queue.

A pull task is a task that has
[PullMessage][google.cloud.tasks.v2beta2.PullMessage] set.
</pre>

<code>.google.cloud.tasks.v2beta2.PullMessage pull_message = 4;</code>
java-tasks/proto-google-cloud-tasks-v2beta2/src/main/java/com/google/cloud/tasks/v2beta2/Task.java