class_docstr: An environment for running on clusters managed by the LSF resource manager.
  
  It is expected that any execution using this ClusterEnvironment was executed
  using the Job Step Manager i.e. ``jsrun``.
  
  This plugin expects the following environment variables:
  
  ``LSB_JOBID``
    The LSF assigned job ID
  
  ``LSB_DJOB_RANKFILE``
    The OpenMPI compatible rank file for the LSF job
  
  ``JSM_NAMESPACE_LOCAL_RANK``
    The node local rank for the task. This environment variable is set by ``jsrun``
  
  ``JSM_NAMESPACE_SIZE``
    The world size for the task. This environment variable is set by ``jsrun``
  
  ``JSM_NAMESPACE_RANK``
    The global rank for the task. This environment variable is set by ``jsrun``
docstr: The world size is read from the environment variable ``JSM_NAMESPACE_RANK``.
docstr_tok: ["The","world","size","is","read","from","the","environment","variable","``","JSM_NAMESPACE_RANK","``","."]
code: def global_rank(self) -> int:
      """The world size is read from the environment variable ``JSM_NAMESPACE_RANK``."""
      global_rank = os.environ.get("JSM_NAMESPACE_RANK")
      if global_rank is None:
          raise ValueError(
              "Cannot determine global rank. Environment variable `JSM_NAMESPACE_RANK` not found."
              " Make sure you run your executable with `jsrun`."
          )
      return int(global_rank)
  
imports: import logging
  import os
  import socket
  from typing import Dict, List
  from typing_extensions import override
  from lightning.fabric.plugins.environments.cluster_environment import ClusterEnvironment
  from lightning.fabric.utilities.cloud_io import get_filesystem
label_desc: Use image node_id 9 for calling the LSFEnvironment obj's underlying member method code with example usage: obj.global_rank() and returns: int