code: def _check_boundary(annot, event_id):
      if event_id is None:
          event_id = dict()
      if "boundary" in annot.description and "boundary" not in event_id:
          warn(
              "The data contains 'boundary' events, indicating data "
              "discontinuities. Be cautious of filtering and epoching around "
              "these events."
          )
  
imports: import os.path
  from os import PathLike
  from pathlib import Path
  import numpy
  from mne.utils.check import _check_option
  from ..._fiff._digitization import _ensure_fiducials_head
  from ..._fiff.constants import FIFF
  from ..._fiff.meas_info import create_info
  from ..._fiff.pick import _PICK_TYPES_KEYS
  from ..._fiff.utils import _find_channels, _read_segments_file
  from ...annotations import Annotations, read_annotations
  from ...channels import make_dig_montage
  from ...defaults import DEFAULTS
  from ...epochs import BaseEpochs
  from ...event import read_events
  from ...utils import Bunch, _check_fname, _check_head_radius, fill_doc, logger, verbose, warn
  from ..base import BaseRaw
  from ._eeglab import _readmat
label_desc: Use image node_id 11 for calling a global function with example usage: _check_boundary(annot, event_id) without return types