code: @BetaApi(
        "The surface for long-running operations is not stable yet and may change in the future.")
    public final OperationFuture<Empty, Struct> trainAgentAsync(String parent) {
  
      TrainAgentRequest request = TrainAgentRequest.newBuilder().setParent(parent).build();
      return trainAgentAsync(request);
    }
docs: Trains the specified agent.
  
  <p>Operation &lt;response: [google.protobuf.Empty][google.protobuf.Empty]&gt;
  
  <p>Sample code:
  
  <pre><code>
  try (AgentsClient agentsClient = AgentsClient.create()) {
  ProjectName parent = ProjectName.of("[PROJECT]");
  agentsClient.trainAgentAsync(parent.toString()).get();
  }
  </code></pre>
  
  @param parent Required. The project that the agent to train is associated with. Format:
  `projects/&lt;Project ID&gt;`.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails