private static void addVariantsFromDocstringReference(@NotNull PsiReference reference, @NotNull CompletionResultSet result) {
      if (reference instanceof DocStringParameterReference) {
        for (PyNamedParameter param : ((DocStringParameterReference)reference).collectParameterVariants()) {
          result.addElement(LookupElementBuilder.createWithIcon(param));
        }
      }
      else if (reference instanceof DocStringTypeReference) {
        for (Object variant : ((DocStringTypeReference)reference).collectTypeVariants()) {
          if (variant instanceof PsiNamedElement) {
            result.addElement(LookupElementBuilder.createWithIcon((PsiNamedElement)variant));
          }
          else {
            result.addElement(LookupElementBuilder.create(variant));
          }
        }
      }
    }
private static void addVariantsFromDocstringReference(@NotNull PsiReference reference, @NotNull CompletionResultSet result)