code: def __call__(self, request: Request) -> str:
      return self.echo_str
  
file_path: ray/doc/source/serve/doc_code/model_composition/language_example.py
imports: import requests
  from starlette.requests import Request
  from ray import serve
  import requests
  from ray import serve
  from ray.serve.handle import DeploymentHandle
  import requests
label_desc: Use image node_id 2 for calling the EchoClass obj's underlying member method code with example usage: obj.__call__(request) and returns: self