Elastica\Query\QueryString::setFields PHP Метод

    public function setFields(array $fields)
    {
        if (!is_array($fields)) {
            throw new InvalidException('Parameter has to be an array');
        }
        return $this->setParam('fields', $fields);
    }

 public function testSearchMultipleFields()
 {
     $str = md5(rand());
     $query = new QueryString($str);
     $expected = array('query' => $str);
     $this->assertEquals(array('query_string' => $expected), $query->toArray());
     $fields = array();
     $max = rand() % 10 + 1;
     for ($i = 0; $i < $max; $i++) {
         $fields[] = md5(rand());
     }
     $query->setFields($fields);
     $expected['fields'] = $fields;
     $this->assertEquals(array('query_string' => $expected), $query->toArray());
     foreach (array(false, true) as $val) {
         $query->setUseDisMax($val);
         $expected['use_dis_max'] = $val;
         $this->assertEquals(array('query_string' => $expected), $query->toArray());
     }
 }