on expects an uploaded file as an answer, the <em class="parameter"><code>Answer</code></em>
			element contains an <em class="parameter"><code>UploadedFileSizeInBytes</code></em> element, and an
				<em class="parameter"><code>UploadedFileKey</code></em> element. <em class="parameter"><code>UploadedFileSizeInBytes</code></em>
			indicates the size of the file the Worker uploaded. <em class="parameter"><code>UploadedFileKey</code></em> is a
			unique identifier for the file, unique with respect to other fil