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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def check_empty_response(self, orig_request, method_config, start_response):
 """If the response from the backend is empty, return a HTTP 204 No Content. Args: orig_request: An ApiRequest, the original request from the user. method_config: A dict, the API config of the method to be called. start_response: A function with semantics defined in PEP-333. Returns: If the backend response was empty, this returns a string containing the response body that should be returned to the user. If the backend response wasn't empty, this returns None, indicating that we should not exit early with a 204. """

    response_config = method_config.get('response', {}).get('body')
    if response_config == 'empty':
      # The response to this function should be empty.  We should return a 204.
      # Note that it's possible that the backend returned something, but we'll
      # ignore it.  This matches the behavior in the Endpoints server.
      cors_handler = self._create_cors_handler(orig_request)
      return util.send_wsgi_no_content_response(start_response, cors_handler)