code: def _check_load_mat(fname, uint16_codec):
      """Check if the mat struct contains 'EEG'."""
      eeg = _readmat(fname, uint16_codec=uint16_codec)
      if "ALLEEG" in eeg:
          raise NotImplementedError(
              "Loading an ALLEEG array is not supported. Please contact"
              "mne-python developers for more information."
          )
      if "EEG" in eeg:  # fields are contained in EEG structure
          eeg = eeg["EEG"]
      eeg = eeg.get("EEG", eeg)  # handle nested EEG structure
      eeg = Bunch(**eeg)
      eeg.trials = int(eeg.trials)
      eeg.nbchan = int(eeg.nbchan)
      eeg.pnts = int(eeg.pnts)
      return eeg
  
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 2 for calling a global function with example usage: _check_load_mat(fname, uint16_codec) and returns: eeg