private function convert($value, $prefixFrom)
    {
        foreach ($this->getConstants() as $constName => $constValue) {
            // process constant if she's does start from reserved prefix and values was equals
            if (0 === strpos($constName, $prefixFrom) && $value === $constValue) {
                return $this->getAppropriateConstValue($prefixFrom, $constName);
            }
        }

        throw new UndefinedMapValueException($this->getClassName(), $value);
    }