Check if setting exists

@param string $key
@return bool
346821
public static function has(string $key) : bool
  {
    $expect = explode('.', $key);
    $config = Config::all();

    foreach($expect as $setting) {
      if (!isset($config[$setting])) return false;
      $config = $config[$setting];
    }

    return true;
  }
661125
public function __isset($key)
    {
        if (parent::__isset($key) === true) {
            return true;
        }

        if (isset($this->viewBag[$key]) === true) {
            return true;
        }

        return isset($this->settings[$key]);
    }
278793
public function has($key)
	{
		$key = $this->id($key);
		return $this->apcu ? apcu_exists($key) : apc_exists($key);
	}
551349
public function has(?string $key) : bool
    {
        return $key === null ? false : isset($this->themes[$key]);
    }
770565
public function exists( $key ) {
		return ! collect( is_array( $key ) ? $key : func_get_args() )->contains(
			function ( $key ) {
				return ! Arr::exists( $this->attributes, $key );
			}
		);
	}
1141206
public function getSetting($key)
    {
        if (array_key_exists($key, $this->settings)) {
            return $this->settings[$key];
        } else {
            return false;
        }
    }
353640
public function exists($key) {
        if (!array_key_exists($key, $this->storage))
            return false;

        if ($this->storage[$key]['expires'] > 0 && time() > $this->storage[$key]['expires'])
            return false;

        return true;
    }
970235
public function __isset($key)
    {
        $k = strtolower($key);
        //check for specialised discovery method
        $methodName = 'has' . ucfirst($k);
        if (method_exists($this, $methodName)) {
            return $this->$methodName();
        } elseif (array_key_exists($k, $this->buildItems) && !is_null($this->buildItems[$k])) {
            return true;
        }
        
        return false;
    }
1029588
protected function exists($key)
    {
        if ($this->enabled && opcache_is_script_cached($this->filePath($key))) {
            return true;
        }
        return file_exists($this->filePath($key));
    }
972886
public function ifExists(string $key): bool
    {
        if ($this->get($key) === false) {
            return false;
        }

        return true;
    }
11042
public function has($key) {
		$this->refresh();
		$keys = explode('.', $key);
		$conf = $this->cache;
		foreach ($keys as $v) {
			if (isset($conf[$v])) {
				$conf = $conf[$v];
			} else {
				return false;
			}
		}
		return true;
	}
4839
public function __isset($key)
	{
		if (isset($this->$key) && (!is_null($this->$key))) {
			return true;
		}
		if (!isset($this->specificationExtensions[$key])) {
			return false;
		}
		return !is_null($this->specificationExtensions[$key]);
	}
888325
function exists($key) {
		$key=$this->fixheader($key);
		return isset($this->headers[$key]);
	}
1105983
public function has(string $key) : bool
    {
        return isset($this->collection[$this->useKey($key)]);
    }
590745
public function exists($key)
    {
        if ($this->enabled) {
            return !$this->pool->getItem($key)->isMiss();
        } else {
            return false;
        }
    }
113950
public function exists($key) {
        $key = $this->secureKey($key);
        
        if (isset($_SESSION[$key])) return true;
        
        return false;
    }
266238
public function exists(?string $key = null) : bool
    {
        $key = $this->constructKey($key);

        return $this->parseKey($key, function ($part, $result) {
            return array_key_exists($part, $result);
        });
    }