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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 unified(old, new):
 """ Returns a generator yielding a unified diff between `old` and `new`. """

        for diff in difflib.ndiff(old.splitlines(), new.splitlines()):
            if diff[0] == " ":
                yield diff
            elif diff[0] == "?":
                continue
            else:
                yield termcolor.colored(diff, "red" if diff[0] == "-" else "green", attrs=["bold"])