code: def accept(self):  # type: () -> str
          
          accept = self.headers.get('Accept')
  
          if not accept or accept == _content_types.ANY:
              return self._default_accept
          else:
              return accept
docs: The content-type for the response to the client.
  
          Returns:
              (str): The value of the header 'Accept' or the user-supplied SAGEMAKER_DEFAULT_INVOCATIONS_ACCEPT
                      environment variable.