code: public final ListEntityTypesPagedResponse listEntityTypes(String parent) {
      ListEntityTypesRequest request = ListEntityTypesRequest.newBuilder().setParent(parent).build();
      return listEntityTypes(request);
    }
docs: Returns the list of all entity types in the specified agent.
  
  <p>Sample code:
  
  <pre><code>
  try (EntityTypesClient entityTypesClient = EntityTypesClient.create()) {
  ProjectAgentName parent = ProjectAgentName.of("[PROJECT]");
  for (EntityType element : entityTypesClient.listEntityTypes(parent.toString()).iterateAll()) {
  // doThingsWith(element);
  }
  }
  </code></pre>
  
  @param parent Required. The agent to list all entity types from. Format: `projects/&lt;Project
  ID&gt;/agent`.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails