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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 _normalize_index(self, index, pipe=None):
 """Convert negative indexes into their positive equivalents."""

        pipe = self.redis if pipe is None else pipe
        len_self = self.__len__(pipe)
        positive_index = index if index >= 0 else len_self + index

        return len_self, positive_index