Cake\ElasticSearch\FilterBuilder::prefix PHP Method

Returns a Prefix filter to filter documents that have fields containing terms with a specified prefix

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

public prefix ( string $field, string $prefix ) : Elastica\Filter\Prefix
$field	string	The field to filter by.
$prefix	string	The prefix to check for.
return	Elastica\Filter\Prefix

    public function prefix($field, $prefix)
    {
        return new Filter\Prefix($field, $prefix);
    }

FilterBuilder