src/Tracker.php
public function run(\Traversable $items, callable $itemCallback)
    {
        $this->start();
        foreach ($items as $item) {
            call_user_func($itemCallback, $this, $item);
        }
        return $this->finish();
    }
public function run(\Traversable $items, callable $itemCallback)
    {
        $this->start();
        foreach ($items as $item) {
            call_user_func($itemCallback, $this, $item);
        }
        return $this->finish();
    }
Iterate over items and track them

@param \Traversable $items
@param callable     $itemCallback  Callback accepts arguments: (Tracker $tracker, $item)
@return Report      The final report