code: def create(self):
          
          # Point to chart repo.
          out = helm(
              "repo",
              "add",
              "jupyterhub",
              self.helm_repo
          )
          out = helm("repo", "update")
  
          # Get token to secure Jupyterhub
          secret_yaml = self.get_security_yaml()
  
          # Get Jupyterhub.
          out = helm(
              "upgrade",
              "--install",
              self.release,
              "jupyterhub/jupyterhub",
              namespace=self.namespace,
              version=self.version,
              input=secret_yaml
          )
          if out.returncode != 0:
              print(out.stderr)
          else:
              print(out.stdout)
docs: Create a single instance of notebook.