'Run a query for entities.
see https://cloud.google.com/datastore/docs/apis/v1beta2/datasets/runQuery
:param body: the body of the query request
:return: the batch of query results.'

def run_query(self, body):

    resp = self.connection.datasets().runQuery(datasetId=self.dataset_id, body=body).execute()
    return resp['batch']
