private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tasks.v2beta3.AppEngineRouting,
            com.google.cloud.tasks.v2beta3.AppEngineRouting.Builder,
            com.google.cloud.tasks.v2beta3.AppEngineRoutingOrBuilder>
        getAppEngineRoutingOverrideFieldBuilder() {
      if (appEngineRoutingOverrideBuilder_ == null) {
        appEngineRoutingOverrideBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tasks.v2beta3.AppEngineRouting,
                com.google.cloud.tasks.v2beta3.AppEngineRouting.Builder,
                com.google.cloud.tasks.v2beta3.AppEngineRoutingOrBuilder>(
                getAppEngineRoutingOverride(), getParentForChildren(), isClean());
        appEngineRoutingOverride_ = null;
      }
      return appEngineRoutingOverrideBuilder_;
    }
<pre>
Overrides for the
[task-level
app_engine_routing][google.cloud.tasks.v2beta3.AppEngineHttpRequest.app_engine_routing].

If set, `app_engine_routing_override` is used for all tasks in
the queue, no matter what the setting is for the
[task-level
app_engine_routing][google.cloud.tasks.v2beta3.AppEngineHttpRequest.app_engine_routing].
</pre>

<code>.google.cloud.tasks.v2beta3.AppEngineRouting app_engine_routing_override = 1;</code>
java-tasks/proto-google-cloud-tasks-v2beta3/src/main/java/com/google/cloud/tasks/v2beta3/AppEngineHttpQueue.java