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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 split(self, sep=TOKENS):
 """ Returns a list of sentences, where each sentence is a list of tokens, where each token is a list of word + tags. """

        if sep != TOKENS:
            return unicode.split(self, sep)
        if len(self) == 0:
            return []
        return [[[x.replace("&slash;", "/") for x in token.split("/")]
            for token in sentence.split(" ")]
                for sentence in unicode.split(self, "\n")]