class_docstr: Interface for collective operations.
  
  Supports communications between multiple processes and multiple nodes. A collective owns a group.
  
  .. warning:: This is an :ref:`experimental <versioning:Experimental API>` feature which is still in development.
code: def world_size(self) -> int:
      ...
  
imports: from abc import ABC, abstractmethod
  from typing import Any, List, Optional
  from torch import Tensor
  from typing_extensions import Self
  from lightning.fabric.utilities.types import CollectibleGroup
label_desc: Use image node_id 3 for calling the Collective obj's underlying member method code with example usage: obj.world_size() without return types