public function testFilterAggregation()
{
$agg = new Filter("filter");
$agg->setFilter(new Term(array("color" => "blue")));
$avg = new Avg("price");
$avg->setField("price");
$agg->addAggregation($avg);
$query = new Query();
$query->addAggregation($agg);
$results = $this->_index->search($query)->getAggregation("filter");
$results = $results['price']['value'];
$this->assertEquals((5 + 8) / 2.0, $results);
}