javaScript onmouseover Изменение изображения

    let img = document.querySelector('img');
    let start = img.src;
    let hover = img.getAttribute('data-hover'); //specified in img tag

    img.onmouseover = () => { img.src = hover; }
    img.onmouseout = () => { img.src = start; } //to revert back to start
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