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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 identify(self, request):
 """Establish claimed identity using request. :param request: Request to extract identity information from. :type request: :class:`morepath.Request`. :return: :class:`morepath.Identity` instance. """

        try:
            authorization = request.authorization
        except ValueError:
            return NO_IDENTITY
        if authorization is None:
            return NO_IDENTITY
        authtype, params = authorization
        auth = parse_basic_auth(authtype, params)
        if auth is None:
            return NO_IDENTITY
        return Identity(userid=auth.username, password=auth.password)