protected function processArrayValue(
        array $value,
        array $settings,
        /*# bool */ $between = false
    )/*# : string */ {
        if ($between) {
            $v1 = $this->processValue($value[0], $settings);
            $v2 = $this->processValue($value[1], $settings);
            return $v1 . ' AND ' . $v2;
        } else {
            $result = [];
            foreach ($value as $val) {
                $result[] = $this->processValue($val, $settings);
            }
            return '(' . join(', ', $result) . ')';
        }
    }