private JPanel createSignaturePanel() {
    mySignature = new GrMethodSignatureComponent("", myProject);
    myTable = new GrParameterTablePanel() {
      @Override
      protected void updateSignature() {
        GrIntroduceParameterDialog.this.updateSignature();
      }

      @Override
      protected void doEnterAction() {
        clickDefaultButton();
      }

      @Override
      protected void doCancelAction() {
        GrIntroduceParameterDialog.this.doCancelAction();
      }
    };

    mySignature.setBorder(IdeBorderFactory.createTitledBorder(GroovyRefactoringBundle.message("signature.preview.border.title"), false));

    Splitter splitter = new Splitter(true);

    splitter.setFirstComponent(myTable);
    splitter.setSecondComponent(mySignature);

    mySignature.setPreferredSize(JBUI.size(500, 100));
    mySignature.setSize(JBUI.size(500, 100));

    splitter.setShowDividerIcon(false);

    final JPanel panel = new JPanel(new BorderLayout());
    panel.add(splitter, BorderLayout.CENTER);
    myForceReturnCheckBox = new JCheckBox(UIUtil.replaceMnemonicAmpersand(
      GroovyBundle.message("introduce.parameter.explicit.return.statement.option.label")
    ));
    panel.add(myForceReturnCheckBox, BorderLayout.NORTH);

    return panel;
  }
private JPanel createSignaturePanel()