def get_bucket_policy(self, bucket_name):
        """
        Get bucket policy of given bucket name.

        :param bucket_name: Bucket name.
        """
        is_valid_bucket_name(bucket_name)

        response = self._url_open("GET",
                                  bucket_name=bucket_name,
                                  query={"policy": ""})
        return response.data
Get bucket policy of given bucket name.

        :param bucket_name: Bucket name.