langchain/memory/chat_message_histories/momento.py/MomentoChatMessageHistory/clear
class MomentoChatMessageHistory:    def clear(self) -> None:
        """Remove the session's messages from the cache.

        Raises:
            SdkException: Momento service or network error.
            Exception: Unexpected response.
        """
        from momento.responses import CacheDelete

        delete_response = self.cache_client.delete(self.cache_name, self.key)
        if isinstance(delete_response, CacheDelete.Success):
            return None
        elif isinstance(delete_response, CacheDelete.Error):
            raise delete_response.inner_exception
        else:
            raise Exception(f"Unexpected response: {delete_response}")