public static void copyCaseValues(@Nullable PsiCaseLabelElementList from,
                                    @Nullable PsiCaseLabelElementList to,
                                    boolean mergeWithDefault) {
    if (from == null || to == null) return;
    for (PsiCaseLabelElement caseValue : from.getElements()) {
      if (mergeWithDefault) {
        to.addBefore(caseValue, to.getFirstChild());
      }
      else {
        to.addAfter(caseValue, to.getLastChild());
      }
    }
  }
public static void copyCaseValues(@Nullable PsiCaseLabelElementList from,
                                    @Nullable PsiCaseLabelElementList to,
                                    boolean mergeWithDefault)