def insert(self, doc, synced=False):
        doc.id = self.get_next_id()
        doc.synced = synced
        try:
            self.db.docs.insert(doc)
        except Exception as e:
            raise DatabaseException(e)
        return doc
def get_metrics(self):
        """Returns the stored metrics.

        The metrics are type checked against the set schema.

        Returns:
          Dictionary of metrics data in the format of the set schema.
        """
        artifact_utils.verify_schema_instance(self._schema, self._values)
        return self._values