/**
* Sets a callback function is called when a batch is loaded
*
* @param \Closure|null $callback The callback function is called when a batch is loaded
* function (Email[] $batch)
*/
public function setBatchCallback(\Closure $callback = null)
{
if ($callback === null) {
// restore default callback
$this->iterator->setBatchCallback($this->onBatchLoaded);
} else {
$iteratorCallback = function ($batch) use($callback) {
call_user_func($this->onBatchLoaded, $batch);
call_user_func($callback, $this->batch);
};
$this->iterator->setBatchCallback($iteratorCallback);
}
}
