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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 tag_wordnet(self, **kwargs):
 """Create wordnet attribute in ``words`` layer. See :py:meth:`~estnltk.text.wordnet_tagger.WordnetTagger.tag_text` method for applicable keyword arguments. """

        global wordnet_tagger
        if wordnet_tagger is None: # cached wn tagger
            wordnet_tagger = WordnetTagger()
        self.__wordnet_tagger = wordnet_tagger
        if len(kwargs) > 0:
            return self.__wordnet_tagger.tag_text(self, **kwargs)
        return self.__wordnet_tagger.tag_text(self, **self.__kwargs)