my( $self, $parent, $id, $title, $pos, $size, $style, $name ) = @_;
    $parent = undef              unless defined $parent;
    $id     = -1                 unless defined $id;
    $title  = ""                 unless defined $title;
    $pos    = wxDefaultPosition  unless defined $pos;
    $size   = wxDefaultSize      unless defined $size;
    $name   = ""                 unless defined $name;