code: private void initialize() {
          this.setContentPane(getJPanel());
          this.setVisible(false);
          this.setTitle(Constant.messages.getString("history.filter.title"));
          if (Model.getSingleton().getOptionsParam().getViewParam().getWmUiHandlingOption() == 0) {
          	this.setSize(600, 300);
          }
          centreDialog();
          this.getRootPane().setDefaultButton(btnApply);
          this.pack();
  	}
docs: This method initializes this