'Shows details for a metadata item, by key, for a server.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#show-metadata-item-details'

def show_server_metadata_item(self, server_id, key):

    (resp, body) = self.get(('servers/%s/metadata/%s' % (server_id, key)))
    body = json.loads(body)
    self.validate_response(schema.set_show_server_metadata_item, resp, body)
    return rest_client.ResponseBody(resp, body)
