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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _subtoken_to_tokens(self, subtokens):
 """ Converts a list of subtoken to a list of tokens. Args: subtokens: a list of integers in the range [0, vocab_size) Returns: a list of strings. """

        concatenated = "".join(subtokens)
        split = concatenated.split("_")
        return [_unescape_token(t + "_") for t in split if t]