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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 md5(self):
 """ An MD5 hash of the current vertices and entities. Returns md5: str, two appended MD5 hashes """

        # first MD5 the points in every entity
        target = '{}{}'.format(
            util.md5_object(bytes().join(e._bytes()
                                         for e in self.entities)),
            self.vertices.md5())

        return target