def generate_id(name, data_id: int) -> str:
    """
    Overview:
        Use ``self.name`` and input ``id`` to generate a unique id for next data to be inserted.
    Arguments:
        - data_id (:obj:`int`): Current unique id.
    Returns:
        - id (:obj:`str`): Id in format "BufferName_DataId".
    """
    return "{}_{}".format(name, str(data_id))