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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 remove_by_threshold(self, threshold=5):
 """ Remove all words at, or below, the provided threshold Args: threshold (int):
 The threshold at which a word is to be \ removed """

        keys = [x for x in self._dictionary.keys()]
        for key in keys:
            if self._dictionary[key] <= threshold:
                self._dictionary.pop(key)
        self._update_dictionary()