def put(self, key: str, val: dict, collection: str = DEFAULT_COLLECTION) -> None:
        """
        Put a key-value pair into the store.

        Args:
            key (str): key
            val (dict): value
            collection (str): collection name

        """
        val = self._flatten_dict_to_json_strings(val)
        self._create_collection_if_not_exist(collection)
        primary_key = [("pk", key)]
        attribute_columns = list(val.items())
        row = tablestore.Row(primary_key, attribute_columns)
        self._tablestore_client.put_row(collection, row)

        Put a key-value pair into the store.

        Args:
            key (str): key
            val (dict): value
            collection (str): collection name

        
llama-index-integrations/storage/kvstore/llama-index-storage-kvstore-tablestore/llama_index/storage/kvstore/tablestore/base.py