static boolean isValidReference(PsiReference reference, boolean unresolvedOnly) {
    if (!(reference instanceof PsiJavaReference)) return false;
    JavaResolveResult[] results = ((PsiJavaReference)reference).multiResolve(false);
    if(results.length == 0) return false;
    if (!unresolvedOnly) {
      for (JavaResolveResult result : results) {
        if (!result.isValidResult()) return false;
        if (result.getElement() instanceof PsiPackage) return false;
      }
    }
    return true;
  }
static boolean isValidReference(PsiReference reference, boolean unresolvedOnly)