private @Nullable Object getSlowData(@NonNls String dataId) {
      if (CommonDataKeys.PSI_ELEMENT.is(dataId)) {
        return getPsiClass();
      }
      else if (UsageView.USAGE_INFO_KEY.is(dataId)) {
        PsiClass psiClass = getPsiClass();
        return psiClass == null ? null : new UsageInfo(psiClass);
      }
      return null;
    }
private @Nullable Object getSlowData(@NonNls String dataId)