https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=56270
break;
        }
        case DecodeContext::ENDIF_ELSE: {
            if (in >= last) return {};
            if (in[0].first == OP_IF) {
                ++in;
                BuildBack(Fragment::OR_I, constructed, true);
            } else if (in[0].first == OP_NOTIF) {
                ++in;
                to_parse.emplace_back(DecodeContext::ANDOR, -1, -1);
                
                to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
            } else {
                return {};
            }
            break;
        }
        }
    }
    if (constructed.size() != 1) return {};
    NodeRef<Key> tl_node = std::move(constructed.front());
    tl_node->DuplicateKeyCheck(ctx);
    
    
    if (!tl_node->IsValidTopLevel()) return {};
    return tl_node;
}
} 
template<typename Ctx>
inline NodeRef<typename Ctx::Key> FromString(const std::string& str, const Ctx& ctx) {