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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 diff(self, other=diff.Diffable.Index, paths=None, create_patch=False, **kwargs):
 """Diff this index against the working copy or a Tree or Commit object For a documentation of the parameters and return values, see Diffable.diff :note: Will only work with indices that represent the default git index as they have not been initialized with a stream. """

        # index against index is always empty
        if other is self.Index:
            return diff.DiffIndex()

        # index against anything but None is a reverse diff with the respective
        # item. Handle existing -R flags properly. Transform strings to the object
        # so that we can call diff on it
        if isinstance(other, string_types):
            other = self.repo.rev_parse(other)
        # END object conversion

        if isinstance(other, Object):
            # invert the existing R flag
            cur_val = kwargs.get('R', False)
            kwargs['R'] = not cur_val
            return other.diff(self.Index, paths, create_patch, **kwargs)
        # END diff against other item handling

        # if other is not None here, something is wrong
        if other is not None:
            raise ValueError("other must be None, Diffable.Index, a Tree or Commit, was %r" % other)

        # diff against working copy - can be handled by superclass natively
        return super(IndexFile, self).diff(other, paths, create_patch, **kwargs)