def METHOD_NAME(message_func, src_feat):
    src_feat_temp = {}
    if src_feat is not None:
        assert isinstance(src_feat,
                          dict), "The input src_feat must be a dict"
        src_feat_temp.update(src_feat)
    src_feat = op.RowReader(src_feat_temp, src_index)
    msg = message_func(src_feat)
    return msg