/**
* @param EntitiesDescriptor|EntityDescriptor $item
*
* @return EntitiesDescriptor
*
* @throws \InvalidArgumentException
*/
public function addItem($item)
{
if (false == $item instanceof self && false == $item instanceof EntityDescriptor) {
throw new \InvalidArgumentException('Expected EntitiesDescriptor or EntityDescriptor');
}
if ($item === $this) {
throw new \InvalidArgumentException('Circular reference detected');
}
if ($item instanceof self) {
if ($item->containsItem($this)) {
throw new \InvalidArgumentException('Circular reference detected');
}
}
$this->items[] = $item;
return $this;
}