public override IPermission Union(IPermission target)
{
PrintingPermission pp = Cast(target);
if (pp == null)
{
return(new PrintingPermission(_Level));
}
if (IsUnrestricted() || pp.IsUnrestricted())
{
return(new PrintingPermission(PermissionState.Unrestricted));
}
if (IsEmpty() && pp.IsEmpty())
{
return(null);
}
PrintingPermissionLevel level = (_Level > pp.Level) ? _Level : pp.Level;
return(new PrintingPermission(level));
}