def METHOD_NAME(self, x, recog_args, char_list=None, rnnlm=None):
    """Recognize x for evaluation.
    :param ndarray x: input acouctic feature (B, T, D) or (T, D)
    :param namespace recog_args: argment namespace contraining options
    :param list char_list: list of characters
    :param paddle.nn.Layer rnnlm: language model module
    :return: N-best decoding results
    :rtype: list
    """
    raise NotImplementedError("recognize method is not implemented")