public static function camelCase($word, bool $ucFirstWord = true): string
    {
        static $words = [];
        
        if (!isset($words[$word])) {
            $words[$word] = str_replace(' ', '', ucwords(strtr($word, '_', ' ')));
            if (!$ucFirstWord) {
                substr_replace($words[$word], $word{0}, 0, 1);
            }
        }
        return $words[$word];
    }