def get_asset_metadata(self, did):
        """
        Retrieve asset metadata for a given did.

        :param did: Asset DID string
        :return: metadata key of the DDO instance
        """
        response = self.requests_session.get(f'{self._base_url}/metadata/{did}').content
        if not response:
            return {}
        try:
            parsed_response = json.loads(response)
        except TypeError:
            parsed_response = None
        except ValueError:
            raise ValueError(response.decode('UTF-8'))
        if parsed_response is None:
            return {}
        return parsed_response['metadata']
Retrieve asset metadata for a given did.

        :param did: Asset DID string
        :return: metadata key of the DDO instance