code: def singleton(cls, session, include=None):
          
          params = build_request_include(include, None)
          url = session._build_url(cls._resource_path())
          process = cls._mk_one(session, singleton=True, include=include)
          return session.get(url, CB.json(200, process), params=params)
docs: Get the a singleton API resource.
  
          Some Helium API resources are singletons. The authorized user
          and organization for a given API key are examples of this.
  
          .. code-block:: python
  
              authorized_user = User.singleton(session)
  
          will retrieve the authorized user for the given
          :class:`Session`
  
          Keyword Args:
  
              include: Resource classes to include