code: def test_sni(loop):
      port = open_port()
      with popen(
          ["dask", "scheduler", "--no-dashboard", f"--port={port}"]
          + tls_args
      ) as s:
          with popen(
              [
                  "dask",
                  "worker",
                  "--no-dashboard",
                  "--scheduler-sni",
                  "localhost",
                  f"tls://127.0.0.1:{port}",
              ]
              + tls_args
          ) as w:
              with Client(
                  f"tls://127.0.0.1:{port}",
                  loop=loop,
                  security=tls_security(),
              ) as c:
                  wait_for_cores(c)
  
file_path: distributed/distributed/cli/tests/test_tls_cli.py
imports: from __future__ import annotations
  from time import sleep
  from distributed import Client
  from distributed.metrics import time
  from distributed.utils import open_port
  from distributed.utils_test import get_cert, new_config_file, popen, tls_only_config, tls_security
label_desc: Use image node_id 3 for calling a global function with example usage: test_sni(loop) without return types