/**
  * Get notebooks repository for given project
  * @param  string $id_or_slug
  * @return Notebooks
  */
 public function notebooksForProject($id_or_slug)
 {
     $repository = new Notebooks($this);
     $repository->setProjectId($id_or_slug);
     return $repository;
 }
 /**
  * Get context for this notebook
  * @return string
  */
 protected function getContext()
 {
     return $this->repository->getContext() . '/notebooks/' . $this->id;
 }