<!DOCTYPE html>

<html>
<head>
<style>
    body {
        margin: 0;
        height: 2000px;
        overflow: hidden; /* hide scrollbars */
    }
    
    .group {
        position: relative;
        width: 250px;
        height: 450px;
    }
    
    .container {
        width: 200px;
        height: 600px;
        outline: 2px solid black;
    }
    
    .box {
        width: 200px;
        height: 200px;
    }

    .before {
        background-color: orange;
        height: 50px;
    }

    .after {
        background-color: blue;
        height: 50px;
    }
    .sticky {
        background-color: green;
        position: sticky;
        top: 300px;
    }
</style>
<script>
    function doTest()
    {
        window.scrollTo(0, 100);
    }
    window.addEventListener('load', doTest, false);
</script>
</head>
<body>
    <div class="group" style="top: 100px">
        <div class="container">
            <div class="before box"></div>
            <div class="sticky box"></div>
            <div class="after box"></div>
        </div>
    </div>

</body>
</html>