Received `false` for a non-boolean attribute `className`. ``` const isTrue = false const myInputRef = useRef(5); const htmlString = { __html : "<span>an</>" } function handleClick(event){ console.log(event); } return ( <div className={isTrue?'red':'green'}><h1 className="question">{text}<hr/></h1> ``` ``` const isTrue = false.toString() const myInputRef = useRef(5); const htmlString = { __html : "<span>an</>" } function handleClick(event){ console.log(event); } return ( <div className={isTrue?'red':'green'}><h1 className="question">{text}<hr/></h1> ```