code: def get_bucket_policy(self, bucket_name):
          
          is_valid_bucket_name(bucket_name)
  
          response = self._url_open("GET",
                                    bucket_name=bucket_name,
                                    query={"policy": ""})
          return response.data
docs: Get bucket policy of given bucket name.
  
          :param bucket_name: Bucket name.