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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 candidates(self, word):
 """ Generate possible spelling corrections for the provided word up to an edit distance of two, if and only when needed Args: word (str):
 The word for which to calculate candidate spellings Returns: set: The set of words that are possible candidates """

        if self.known([word]):  # short-cut if word is correct already
            return {word}
        # get edit distance 1...
        res = [x for x in self.edit_distance_1(word)]
        tmp = self.known(res)
        if tmp:
            return tmp
        # if still not found, use the edit distance 1 to calc edit distance 2
        if self._distance == 2:
            tmp = self.known([x for x in self.__edit_distance_alt(res)])
            if tmp:
                return tmp
        return {word}