As been discussed before, this is kind of awkward but results out of the entity selector's lack of flexibility. However, still, there might be a cleaner way: <code>$.wikibase.entityselector</code> inherits from <code>$.ui.suggester</code>. <code>$.ui.suggester</code> allows specifying a <code>source</code> option which should map to <code>_request()</code>. See <code>$.ui.suggester._create()</code>. Basically, you would just submit your <code>_request()</code> method as <code>source</code> option to the entity selector and, finally, you might even get around overwriting the entity selector.