/**
* Return this collection minus the elements of the passed collection
*
* @param $collec Another Collection containing the same class of elements
*/
public function diff(Collection $collec)
{
if (empty($this->className)) {
$this->className = $collec->className();
}
foreach ($collec->collected as $id => $c) {
if ($this->get($id)) {
$this->remove($id);
}
}
return $this;
}
