/**
* Compute the union of this collection and the given collection.
*
* @param CollectionInterface $collection The collection to intersect.
*
* @return CollectionInterface
*/
public function union($collection)
{
$union = clone $this;
/** @var ModelInterface $otherModel */
foreach ($collection->diff($this) as $otherModel) {
$union->push($otherModel);
}
return $union;
}
