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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 wrefs(self, index = None, recurse=True):
 """Returns a list of word references, these can be Words but also Morphemes or Phonemes. Arguments: index (int or None):
 If set to an integer, will retrieve and return the n'th element (starting at 0) instead of returning the list of all """

        targets =[]
        self._helper_wrefs(targets, recurse)
        if index is None:
            return targets
        else:
            return targets[index]