@classmethod
def get_named_cookie_from_string(cls, cookie_string, cookie_name,
    request_url=None, timestamp=None):
    """
        A cookie string may contain multiple cookies, parse the cookie
        string and return the last cookie in the string matching the
        cookie name or None if not found.

        This is basically a utility wrapper around the parse() class
        method which iterates over what parse() returns looking for
        the specific cookie.

        When cookie_name appears more than once the last instance is
        returned rather than the first because the ordering sequence
        makes the last instance the current value.
        """
    target_cookie = None
    cookies = cls.parse(cookie_string)
    for cookie in cookies:
        if cookie.key == cookie_name:
            target_cookie = cookie
    if timestamp is not None:
        target_cookie.timestamp = timestamp
    if request_url is not None:
        target_cookie.normalize(request_url)
    return target_cookie
