/li><li><i>IEIFLAG_OFFLINE</i> - Tells the extractor not to connect to the
         Internet for any content which isn't available offline.</li><li><i>IEIFLAG_SCREEN</i> - Render the item as if for the screen (exclusive
	with <i>IEIFLAG_ASPECT</i>.</li><li><i>IEIFLAG_QUALITY</i> - Request a higher quality image.  This may be
	slower.</li></ul>
Note that the <i>IEIFLAG_ASYNC</i> option is not supported: whilst some thumbnail
generators support asynchronous generation, the host needs to create a background
th