@Nullable
  public static PsiElement getOnlyNonWhitespaceChild(PsiElement element) {
    PsiElement onlyChild = null;
    for (PsiElement child = element.getFirstChild(); child != null; child = child.getNextSibling()) {
      if (DuplocatorUtil.isIgnoredNode(element) || child.getTextLength() == 0) {
        continue;
      }
      if (onlyChild != null) {
        return null;
      }
      onlyChild = child;
    }
    return onlyChild;
  }
@Nullable
  public static PsiElement getOnlyNonWhitespaceChild(PsiElement element)