private static void findReturnValueInside(@NotNull PsiElement node, Collection<PsiElement> offenders) {
      for (PsiElement child = node.getFirstChild(); child != null; child = child.getNextSibling()) {
        if (child instanceof PyFunction || child instanceof PyClass) continue; // ignore possible inner functions and classes
        if (child instanceof PyReturnStatement) {
          if (((PyReturnStatement)child).getExpression() != null) offenders.add(child);
        }
        findReturnValueInside(child, offenders);
      }
    }
private static void findReturnValueInside(@NotNull PsiElement node, Collection<PsiElement> offenders)