src/Config/ConfigAbstract.php
final protected function existOrFail(string $key): void
    {
        if (!isset($this->env[$key])) {
            throw new MissingConfigException($key, static::class);
        }
    }
final protected function existOrFail(string $key): void
    {
        if (!isset($this->env[$key])) {
            throw new MissingConfigException($key, static::class);
        }
    }
final protected function existOrFail ( string $ key ) : void { if ( ! isset ( $ this -> env [ $ key ] ) ) { throw new MissingConfigException ( $ key , static :: class ) ; } }
Check if a specific env variable is set or not.
If it isn't set, throw an exception.

@param string $key

@throws MissingConfigException
Check if a specific env variable is set or not . If it isn t set throw an exception .