code: def _start(name, f, log):
      import daemonize
  
      pidfile = var.pidfile(name)
      if os.path.exists(pidfile):
          raise Running(name, pidfile)
      util.ensure_dir(os.path.dirname(pidfile))
      # Save original log level to workaround issue with daemonization
      # (see note in _run).
      log_level = log.getEffectiveLevel()
      daemon = daemonize.Daemonize(
          app=name,
          action=lambda: _run(f, log, log_level),
          pid=pidfile,
          keep_fds=_log_fds(log),
      )
      daemon.start()
  
imports: import os
  import logging
  import psutil
  from guild import var
  from guild import util
label_desc: Use image node_id 4 for calling a global function with example usage: _start(name, f, log) without return types