Collapse facet from Facet API and Search API

Hi,

I am using facet api and search api and I am trying to make the facets collapsible through collapsiblock. But even though the selectors are pretty straight forward, I can't do it....

A typical facet is:

<div class="block block-facetapi collapsiblock-processed" id="block-facetapi-nps-zjsjqhpw-iinw21semqkhwrrbfk6">
	<h2>Filters</h2>
	<div class="content">
		<div class="item-list">
			<h3>Search found 5 items</h3>
			<ul>
				<li class="first last">[all items]</li>
			</ul>
		</div>  
	</div>
</div>

And the selectors I use are:
div.block
h2:first
div.content

It should work! Right?

Any help would be very welcome...

P.S. And all other blocks are collapsible.