code: def get_response_headers(self, *args, **kwargs):
          
          if self.response_headers:
              return self._unpack_headers(self.response_headers)
docs: A convenience method for obtaining the headers that were sent from the
          S3 server.
  
          The AWS S3 API depends upon setting headers. This method is used by the
          head_object API call for getting a S3 object's metadata.