/** {@inheritdoc} */
public function getIterator()
{
$canMultisort = $this->sortFlags !== null;
$array = $this->source->tryGetArrayCopy();
$it = $this->trySortBySingleField($array, $canMultisort);
if ($it !== null) {
return $it;
}
return $this->sortByMultipleFields($array, $canMultisort);
}