public function withinBox($startLatitude, $startLongitude, $endLatitude, $endLongitude)
    {
        $this->predicates[] = '[' . $this->processFloat($startLatitude) . ',' . $this->processFloat($startLongitude) .
            ' TO ' . $this->processFloat($endLatitude) . ',' . $this->processFloat($endLongitude) . ']';

        return $this;
    }