sub permits { 
    my ($self, $mask) = @_;
    return (($self->{perms} & $mask) =~ y/\0//c);
}

##</code><code>##

sub permits {
    my ($self, $mask) = @_;
    $mask &= $self->{perms};
    return ($mask =~ y/\0//c ? $mask : "");
}