code: def _is_sys_msg(line):
      """Flag lines from eyelink ASCII file that contain a known system message.
  
      Some lines in eyelink files are system outputs usually
      only meant for Eyelinks DataViewer application to read.
      These shouldn't need to be parsed.
  
      Parameters
      ----------
      line : string
          single line from Eyelink asc file
  
      Returns
      -------
      bool :
          True if any of the following strings that are
          known to indicate a system message are in the line
  
      Notes
      -----
      Examples of eyelink system messages:
      - ;Sess:22Aug22;Tria:1;Tri2:False;ESNT:182BFE4C2F4;
      - ;NTPT:182BFE55C96;SMSG:__NTP_CLOCK_SYNC__;DIFF:-1;
      - !V APLAYSTART 0 1 library/audio
      - !MODE RECORD CR 500 2 1 R
      """
      return "!V" in line or "!MODE" in line or ";" in line
  
imports: import re
  from datetime import datetime, timedelta, timezone
  import numpy
  from ..._fiff.constants import FIFF
  from ..._fiff.meas_info import create_info
  from ...annotations import Annotations
  from ...utils import _check_pandas_installed, logger, warn
label_desc: Use image node_id 6 for calling a global function with example usage: _is_sys_msg(line) and returns: unknown