private void addDocReference(ResolveResultList ret, PyExpression qualifier, PyType qualifierType) {
    PsiElement docstring = null;
    if (qualifierType instanceof PyClassType) {
      PyClass qualClass = ((PyClassType)qualifierType).getPyClass();
      docstring = qualClass.getDocStringExpression();
    }
    else if (qualifierType instanceof PyModuleType) {
      PyFile qualModule = ((PyModuleType)qualifierType).getModule();
      docstring = qualModule.getDocStringExpression();
    }
    else if (qualifier instanceof PyReferenceExpression) {
      PsiElement qual_object = ((PyReferenceExpression)qualifier).getReference(myContext).resolve();
      if (qual_object instanceof PyDocStringOwner) {
        docstring = ((PyDocStringOwner)qual_object).getDocStringExpression();
      }
    }
    ret.poke(docstring, RatedResolveResult.RATE_HIGH);
  }
private void addDocReference(ResolveResultList ret, PyExpression qualifier, PyType qualifierType)