code: public final ListSessionEntityTypesPagedResponse listSessionEntityTypes(SessionName parent) {
      ListSessionEntityTypesRequest request =
          ListSessionEntityTypesRequest.newBuilder()
              .setParent(parent == null ? null : parent.toString())
              .build();
      return listSessionEntityTypes(request);
    }
docs: Returns the list of all session entity types in the specified session.
  
  <p>Sample code:
  
  <pre><code>
  try (SessionEntityTypesClient sessionEntityTypesClient = SessionEntityTypesClient.create()) {
  SessionName parent = SessionName.of("[PROJECT]", "[SESSION]");
  for (SessionEntityType element : sessionEntityTypesClient.listSessionEntityTypes(parent).iterateAll()) {
  // doThingsWith(element);
  }
  }
  </code></pre>
  
  @param parent Required. The session to list all session entity types from. Format:
  `projects/&lt;Project ID&gt;/agent/sessions/&lt;Session ID&gt;` or `projects/&lt;Project
  ID&gt;/agent/environments/&lt;Environment ID&gt;/users/&lt;User ID&gt;/
  sessions/&lt;Session ID&gt;`. If `Environment ID` is not specified, we assume default
  'draft' environment. If `User ID` is not specified, we assume default '-' user.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails