Elastica\QueryBuilder\DSL\Aggregation::filter PHP Method

    public function filter($name, AbstractQuery $filter = null)
    {
        return new FilterAggregation($name, $filter);
    }

 /**
  * @group unit
  * @expectedException \Elastica\Exception\InvalidException
  */
 public function testFilteredInvalid()
 {
     $queryDSL = new DSL\Aggregation();
     $queryDSL->filter(null, $this);
 }