pylint: Skip unused-private-member for unsupported cases
    
    > This mangling is done without regard to the syntactic position of the
    identifier, as long as it occurs within the definition of a class.
    
    `__set_attr` is called for instance of the class within its
    classmethod.
    
    Fixes: https://pagure.io/freeipa/issue/9117
    Signed-off-by: Stanislav Levin <slev@altlinux.org>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>