src/Config/ArrayConfig.php
public function has($key)
    {
        $chunks = $this->path($key);
        $value  = $this->config;

        while (($chunk = array_shift($chunks)) !== null) {
            if (!array_key_exists($chunk, $value)) {
                return false;
            }

            $value = $value[$chunk];
        }

        return true;
    }
public function has($key)
    {
        $chunks = $this->path($key);
        $value  = $this->config;

        while (($chunk = array_shift($chunks)) !== null) {
            if (!array_key_exists($chunk, $value)) {
                return false;
            }

            $value = $value[$chunk];
        }

        return true;
    }
{@inheritdoc}