code: public function madd($items, $duration = 0, $dependency = null)
      {
          return $this->multiAdd($items, $duration, $dependency);
      }
docs: Stores multiple items in cache. Each item contains a value identified by a key.
  If the cache already contains such a key, the existing value and expiration time will be preserved.
  
  @param array $items the items to be cached, as key-value pairs.
  @param int $duration default number of seconds in which the cached values will expire. 0 means never expire.
  @param Dependency $dependency dependency of the cached items. If the dependency changes,
  the corresponding values in the cache will be invalidated when it is fetched via [[get()]].
  This parameter is ignored if [[serializer]] is false.
  @return array array of failed keys
  @deprecated This method is an alias for [[multiAdd()]] and will be removed in 2.1.0.