public Builder mergeAppEngineHttpTarget(
        com.google.cloud.tasks.v2beta2.AppEngineHttpTarget value) {
      if (appEngineHttpTargetBuilder_ == null) {
        if (targetTypeCase_ == 3
            && targetType_
                != com.google.cloud.tasks.v2beta2.AppEngineHttpTarget.getDefaultInstance()) {
          targetType_ =
              com.google.cloud.tasks.v2beta2.AppEngineHttpTarget.newBuilder(
                      (com.google.cloud.tasks.v2beta2.AppEngineHttpTarget) targetType_)
                  .mergeFrom(value)
                  .buildPartial();
        } else {
          targetType_ = value;
        }
        onChanged();
      } else {
        if (targetTypeCase_ == 3) {
          appEngineHttpTargetBuilder_.mergeFrom(value);
        } else {
          appEngineHttpTargetBuilder_.setMessage(value);
        }
      }
      targetTypeCase_ = 3;
      return this;
    }
<pre>
App Engine HTTP target.

An App Engine queue is a queue that has an
[AppEngineHttpTarget][google.cloud.tasks.v2beta2.AppEngineHttpTarget].
</pre>

<code>.google.cloud.tasks.v2beta2.AppEngineHttpTarget app_engine_http_target = 3;</code>
java-tasks/proto-google-cloud-tasks-v2beta2/src/main/java/com/google/cloud/tasks/v2beta2/Queue.java