sub buildGui {
  $goMainWindow = new MainWindow;

#pack your Exit button first in the list
   my ($oExit) = $goMainWindow->Button(-text => 'Exit',
                      -command => sub{exit},
                     )->pack(
                      -padx => '5',
                      -pady => '5',
                      -side => 'bottom',
                     );


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