langchain/vectorstores/analyticdb.py/AnalyticDB/delete_collection
class AnalyticDB:    def delete_collection(self) -> None:
        self.logger.debug("Trying to delete collection")
        with Session(self._conn) as session:
            collection = self.get_collection(session)
            if not collection:
                self.logger.error("Collection not found")
                return
            session.delete(collection)
            session.commit()