Checks if user represented by token is in group.

        :param user_token: string representing token

        :param group: group's name

def group_authenticated(self, user_token, group):
        """Checks if user represented by token is in group.

        :param user_token: string representing token

        :param group: group's name
        """
        if self.authenticated(user_token):
            token = self.token_storage.get(user_token)
            groups = self.get_groups(token.username)
            if group in groups:
                return True

        return False