private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tasks.v2beta2.PullTarget,
            com.google.cloud.tasks.v2beta2.PullTarget.Builder,
            com.google.cloud.tasks.v2beta2.PullTargetOrBuilder>
        getPullTargetFieldBuilder() {
      if (pullTargetBuilder_ == null) {
        if (!(targetTypeCase_ == 4)) {
          targetType_ = com.google.cloud.tasks.v2beta2.PullTarget.getDefaultInstance();
        }
        pullTargetBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tasks.v2beta2.PullTarget,
                com.google.cloud.tasks.v2beta2.PullTarget.Builder,
                com.google.cloud.tasks.v2beta2.PullTargetOrBuilder>(
                (com.google.cloud.tasks.v2beta2.PullTarget) targetType_,
                getParentForChildren(),
                isClean());
        targetType_ = null;
      }
      targetTypeCase_ = 4;
      onChanged();
      return pullTargetBuilder_;
    }
<pre>
Pull target.

A pull queue is a queue that has a
[PullTarget][google.cloud.tasks.v2beta2.PullTarget].
</pre>

<code>.google.cloud.tasks.v2beta2.PullTarget pull_target = 4;</code>
java-tasks/proto-google-cloud-tasks-v2beta2/src/main/java/com/google/cloud/tasks/v2beta2/Queue.java