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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 cookies(self) -> Mapping[str, str]: """Return request cookies. A read-only dictionary-like object. """

        raw = self.headers.get(hdrs.COOKIE, '')
        parsed = SimpleCookie(raw)
        return MappingProxyType(
            {key: val.value for key, val in parsed.items()})