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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 update_cookies(self, cookies: Optional[LooseCookies]) -> None: """Update request cookies header."""

        if not cookies:
            return

        c = SimpleCookie()
        if hdrs.COOKIE in self.headers:
            c.load(self.headers.get(hdrs.COOKIE, ''))
            del self.headers[hdrs.COOKIE]

        if isinstance(cookies, Mapping):
            iter_cookies = cookies.items()
        else:
            iter_cookies = cookies  # type: ignore
        for name, value in iter_cookies:
            if isinstance(value, Morsel):
                # Preserve coded_value
                mrsl_val = value.get(value.key, Morsel())
                mrsl_val.set(value.key, value.value, value.coded_value)  # type: ignore  # noqa
                c[name] = mrsl_val
            else:
                c[name] = value  # type: ignore

        self.headers[hdrs.COOKIE] = c.output(header='', sep=';').strip()