public function has($key)
    {
        $flashMessages = $this->storage->get(self::FLASH_KEY);
        return isset($flashMessages[$key]);
    }
public function has($key)
    {
        $flashMessages = $this->storage->get(self::FLASH_KEY);
        return isset($flashMessages[$key]);
    }
public function has ( $ key ) { $ flashMessages = $ this -> storage -> get ( self :: FLASH_KEY ) ; return isset ( $ flashMessages [ $ key ] ) ; }
Checks whether message key exists

@param string $key
@return boolean
Checks whether message key exists