Pimcore\Logger::warn PHP Method

    public static function warn($m, $context = [])
    {
        self::log($m, "warning", $context);
    }

 /**
  * Deletes a single parameter which was set with "setParams" or "setParam"
  *
  * @param string | integer $key
  * @return \Pimcore\Mail Provides fluent interface
  */
 public function unsetParam($key)
 {
     if (is_string($key) || is_integer($key)) {
         unset($this->params[$key]);
     } else {
         \Logger::warn('$key has to be a string - unsetParam ignored!');
     }
     return $this;
 }