@Nullable
  private JPanel createParametersPanel () {
    myThisClassesMap = MoveInstanceMembersUtil.getThisClassesToMembers(myMethod);
    myOldClassParameterNameFields = new HashMap<>();
    if (myThisClassesMap.size() == 0) return null;
    JPanel panel = new JPanel(new VerticalFlowLayout(VerticalFlowLayout.TOP, 0, 0, true, true));
    for (PsiClass aClass : myThisClassesMap.keySet()) {
      final String text = JavaRefactoringBundle.message("move.method.this.parameter.label", ObjectUtils.notNull(aClass.getName(), ""));
      panel.add(new TitledSeparator(text, null));

      String suggestedName = MoveInstanceMethodHandler.suggestParameterNameForThisClass(aClass);
      final EditorTextField field = new EditorTextField(suggestedName, getProject(), JavaFileType.INSTANCE);
      field.setMinimumSize(new Dimension(field.getPreferredSize()));
      myOldClassParameterNameFields.put(aClass, field);
      panel.add(field);
    }
    panel.setBorder(BorderFactory.createEmptyBorder(5, 0, 5, 0));
    return panel;
  }
@Nullable
  private JPanel createParametersPanel ()