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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 _is_subspan(self, m, span):
 """ Tests if mention m is subspan of span, where span is defined specific to mention type. """

        return (
            m.sentence.id == span[0]
            and m.char_start >= span[1]
            and m.char_end <= span[2]
        )