protected function setValue($key, $value, $duration)
    {
        return $this->useApcu ? apcu_store($key, $value, $duration) : apc_store($key, $value, $duration);
    }
protected function setValue($key, $value, $duration)
    {
        return $this->useApcu ? apcu_store($key, $value, $duration) : apc_store($key, $value, $duration);
    }
Stores a value identified by a key in cache.
This is the implementation of the method declared in the parent class.

@param string $key the key identifying the value to be cached
@param mixed $value the value to be cached. Most often it's a string. If you have disabled [[serializer]],
it could be something else.
@param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
@return bool true if the value is successfully stored into cache, false otherwise.