code: def register_cluster_backend(backend: Type[AbstractClusterBackend]):
      _cluster_backend_types[backend.name] = backend
      return backend
  
imports: from abc import ABC, abstractmethod
  from typing import AsyncGenerator, Dict, List, Optional, Type
  from ..core import NodeRole
label_desc: Use image node_id 1 for calling a global function with example usage: register_cluster_backend(backend) and returns: backend