Cake\ElasticSearch\FilterBuilder::exists PHP Method

Returns an Exists filter object setup to filter documents having a property present or not set to null.

See also: http://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-exists-filter.html

public exists ( string $field ) : Elastica\Filter\Exists
$field	string	The field to check for existance.
return	Elastica\Filter\Exists

    public function exists($field)
    {
        return new Filter\Exists($field);
    }

FilterBuilder