class_docstr: A runner to execute commands on an array of machines. This runner
  is inspired by Nezha (https://github.com/zhuzilin/NeZha).
code: def __init__(self):
      self.processes = {}
      self.master_send_conns = {}
      self.master_recv_conns = {}
  
file_path: colossalai/colossalai/cli/launcher/multinode_runner.py
imports: from multiprocessing import Pipe, Process
  from multiprocessing import connection
  import click
  import fabric
  from .hostinfo import HostInfo, HostInfoList
label_desc: Use image node_id 1 to create a new MultiNodeRunner object  with example: obj = MultiNodeRunner()