code: def test_command_line(self):
      fiber.init(use_bash=False)
      try:
          p = fiber.Process(name="test_command_line")
          popen = fspawn.Popen(p, backend="docker", launch=False)
  
          cmd = popen.get_command_line(
              host="127.0.0.1", port="8000", id=1
          )
      finally:
          fiber.init(use_bash=True)
      assert cmd == [
          "/usr/local/bin/python",
          "-c",
          'import sys;import os;import socket;import struct;import fiber;import fiber.util;from multiprocessing import spawn, reduction;sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM);sock.connect(("127.0.0.1", 8000));conn = sock;conn.send(struct.pack("<I", 1));fd = conn.fileno();exitcode = fiber.util.spawn_prepare(fd);sys.exit(exitcode)',
          "--multiprocessing-fork",
      ]
  
file_path: fiber/tests/test_popen.py
imports: import multiprocessing
  import io
  import re
  import time
  import logging
  import socket
  import fiber
  import fiber.popen_fiber_spawn
  import docker
  import pytest
label_desc: Use image node_id 3 for calling the TestPopen obj's underlying member method code with example usage: obj.test_command_line() without return types