@classmethod
def get_roles(cls, login):
    """Return the roles of an user

        :param login: str, login attribute of the user
        :rtype: list of str (name of the roles)
        """
    roles = [login]
    user = cls.query().filter(cls.login == login).one_or_none()
    if user:
        for role in user.roles:
            roles.extend(role.roles_name)
    return list(set(roles))
