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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 edit_distance_1(self, word):
 """ Compute all strings that are one edit away from `word` using only the letters in the corpus Args: word (str):
 The word for which to calculate the edit distance Returns: set: The set of strings that are edit distance one from the \ provided word """

        word = word.lower()
        if self._check_if_should_check(word) is False:
            return {word}
        letters = self._word_frequency.letters
        splits = [(word[:i], word[i:]) for i in range(len(word) + 1)]
        deletes = [L + R[1:] for L, R in splits if R]
        transposes = [L + R[1] + R[0] + R[2:] for L, R in splits if len(R) > 1]
        replaces = [L + c + R[1:] for L, R in splits if R for c in letters]
        inserts = [L + c + R for L, R in splits for c in letters]
        return set(deletes + transposes + replaces + inserts)