scripttransform.js

<script>
 var smscript = document.createElement('script');
    smscript.type = 'text/javascript';
    smscript.async = true;
    smscript.src = 'https://smartasset.com/snippet.js';
    var s = document.getElementsByTagName('script')[0];   
    s.parentNode.insertBefore(smscript, s);  
</script>

// above script is equivalent to
<script async src="https://smartasset.com/snippet.js"></script>