private static @Nullable PsiClass extractClass(LookupElement lookupElement) {
    final Object object = lookupElement.getObject();
    if (object instanceof PsiClass) {
      return (PsiClass)object;
    }
    if (object instanceof PsiMethod && ((PsiMethod)object).isConstructor()) {
      return ((PsiMethod)object).getContainingClass();
    }
    return null;
  }
private static @Nullable PsiClass extractClass(LookupElement lookupElement)