ArrayBuffer

const buffer = new ArrayBuffer(64)

const buffer = new ArrayBuffer(64)
const newBuffer = buffer.slice(32, 8)

const downloadBlob = (url, callback) => {
	const xhr = new XMLHttpRequest()
	xhr.open('GET', url)
	xhr.responseType = 'arraybuffer'
<span style="color:#a6e22e">xhr</span>.<span style="color:#a6e22e">onload</span> <span style="color:#f92672">=</span> () =&gt; {
<span style="color:#a6e22e">callback</span>(<span style="color:#a6e22e">xhr</span>.<span style="color:#a6e22e">response</span>)
}

<span style="color:#a6e22e">xhr</span>.<span style="color:#a6e22e">send</span>(<span style="color:#66d9ef">null</span>)
}