/**
* Add an item to this collection.
*
* @param $object
* @param null $key
* @return mixed
* @throws Exception
*/
public function set($object, $key = null)
{
if (is_null($key)) {
return $this->attributes[] = $object;
}
if (array_key_exists($key, $this->attributes)) {
throw new Exception("Key '{$key}' already exists");
}
return Arr::set($key, $object, $this->attributes);
}
