/**
* Instance a model
*
* @param string $model Model name to instance
* @throws \InvalidArgumentException case param $model is not a string
* @throws \RuntimeException case model do not exists
* @return object
*/
protected function model($model)
{
if ($this->modelDispatcher === null) {
ControllerException::modelDispatcherNotDefined();
} elseif ($this->modelsNamespace === null) {
ControllerException::modelsNamespaceNotDefined();
}
return $this->modelDispatcher->dispatch($this->getModelsNamespace(), $model);
}