def get_schema(self, refresh: bool = False) -> str:
        """Get the schema of the NebulaGraph store."""
        if self.schema and not refresh:
            return self.schema
        self.refresh_schema()
        logger.debug(f"get_schema()\nschema: {self.schema}")
        return self.schema
Get the schema of the NebulaGraph store.
llama-index-integrations/graph_stores/llama-index-graph-stores-nebula/llama_index/graph_stores/nebula/nebula_graph_store.py