@Nullable
  private Pair<PsiElement/* doc anchor */, PsiElement /* original element */> getDocInfo() {
    PsiElement docAnchor = SoftReference.dereference(myDocAnchor);
    if (docAnchor == null) {
      return null;
    }
    PsiElement originalElement = SoftReference.dereference(myOriginalElement);
    if (originalElement == null) {
      return null;
    }
    return Pair.create(docAnchor, originalElement);
  }
@Nullable
  private Pair<PsiElement/* doc anchor */, PsiElement /* original element */> getDocInfo()