public function trackByListener($resource, $callback, $eventsMask = FilesystemEvent::ALL)
    {
        $this->track($trackingId = md5((string) $resource.$eventsMask), $resource, $eventsMask);
        $this->addListener($trackingId, $callback);
    }
public function trackByListener($resource, $callback, $eventsMask = FilesystemEvent::ALL)
    {
        $this->track($trackingId = md5((string) $resource.$eventsMask), $resource, $eventsMask);
        $this->addListener($trackingId, $callback);
    }
public function trackByListener ( $ resource , $ callback , $ eventsMask = FilesystemEvent :: ALL ) { $ this -> track ( $ trackingId = md5 ( ( string ) $ resource . $ eventsMask ) , $ resource , $ eventsMask ) ; $ this -> addListener ( $ trackingId , $ callback ) ; }
Tracks specific resource change by provided callback.

@param ResourceInterface|string $resource   resource to track
@param callable                 $callback   callback to call on change
@param integer                  $eventsMask event types bitmask
Tracks specific resource change by provided callback .