public function push(Model $model, $key = null)
{
if (is_null($key)) {
$model->setKey(count($this->models));
return $this->models[] = $model;
}
if (is_array($key)) {
$key = implode("-", $key);
}
if (array_key_exists($key, $this->models)) {
return $this->models[$key];
}
$model->setKey($key);
return $this->models[$key] = $model;
}
