private static function keysExist(array $keys, array $subject) : bool
    {
        foreach ($keys as $key) {
            if (!isset($subject[$key])) {
                return false;
            }
        }
        return true;
    }
private static function keysExist(array $keys, array $subject) : bool
    {
        foreach ($keys as $key) {
            if (!isset($subject[$key])) {
                return false;
            }
        }
        return true;
    }
private static function keysExist ( array $ keys , array $ subject ) : bool { foreach ( $ keys as $ key ) { if ( ! isset ( $ subject [ $ key ] ) ) { return false ; } } return true ; }
Does an array have the expected keys

@param  array $keys
@param  array $subject
@return bool
Does an array have the expected keys