sub _install_property{
    my ($label, $hash, $opt, $caller) = @_;

#    my $caller = caller(0); # we get here via "goto", so caller(0) is right
    $PROP_DATA_FOR{ $caller }{$label} = $hash;
    my $options = _merge_options( $caller, $opt );
    if ( exists $options->{privacy} && $options->{privacy} eq 'public' ) {
        no strict 'refs';
        *{ "$caller\::$label" } =
            ($options->{set_hook} || $options->{get_hook})
                ? _gen_hook_accessor( $hash, $label, $options->{get_hook},
                                                 $options->{set_hook} )
                : _gen_accessor( $hash ) ;
        $PUBLIC_PROPS_FOR{ $caller }{ $label } = 1;
    }
    return;
}