I don't understand the curly brackets

{
   my @command = ($0,@ARGV);
   $Window->command(?@command?);
}
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What do you suppose that does? Is it an artifact of Tcl code? Neither could I find where command and group are inherited from. But, simply including in the initWindow subroutine:

#...
sub initWindow {
    print STDERR "Initializing Tk window...\n" if ($opt_debug);
    $Window = MainWindow->new(-title  => "Perlmonks Chat");
    $Window->group($Window);
#...         ^^^^^^
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is enough to create a WindowMaker icon. Like you, I'm not comfortable that something works, when I don't know why it works - maybe it's not working the way I imagine.

What's the best way to research inheritance in an Object Oriented program? How do I know I've found the attributes that are inherited?
UPDATE

I found this concerning Tk::Wm.
And the following descriptions.

$toplevel->command(?value?) If value is specified, this method stores value in $toplevel's WM_COMMAND property for use by the window manager or session manager and returns an empty string. Value must have proper list structure; the elements should contain the words of the command used to invoke the application. If value isn't specified then the method returns the last value set in a command method for $toplevel. If value is specified as an empty string, the method deletes the WM_COMMAND property from $toplevel.

$toplevel->group(?$widget?) If $widget is specified, it is the the leader of a group of related windows. The window manager may use this information, for example, to unmap all of the windows in a group when the group's leader is iconified. $widget may be specified as an empty string to remove $toplevel from any group association. If $widget is specified then the method returns an empty string; otherwise it returns the $toplevel's current group leader, or an empty string if $toplevel isn't part of any group.

That helps a bit. But I'm not sure that I understand the relationship in the Object hierarchy, even for all that.

mkmcconn