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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 parse_auth_token_from_request(self, auth_header):
 """ Parses and returns Auth token from the request header. Raises `falcon.HTTPUnauthoried exception` with proper error message """

        if not auth_header:
            raise falcon.HTTPUnauthorized(
                description='Missing Authorization Header')

        parts = auth_header.split()

        if parts[0].lower() != self.auth_header_prefix.lower():
            raise falcon.HTTPUnauthorized(
                description='Invalid Authorization Header: '
                            'Must start with {0}'.format(self.auth_header_prefix))

        elif len(parts) == 1:
            raise falcon.HTTPUnauthorized(
                description='Invalid Authorization Header: Token Missing')
        elif len(parts) > 2:
            raise falcon.HTTPUnauthorized(
                description='Invalid Authorization Header: Contains extra content')

        return parts[1]