code: def test_io_egi_evokeds_mff(idx, cond, tmax, signals, bads):
      """Test reading evoked MFF file."""
      pytest.importorskip("mffpy", "0.5.7")
  
      pytest.importorskip("defusedxml")
      # expected n channels
      n_eeg = 256
      n_ref = 1
      n_card = 3
      n_pns = 2  # 1 ECG + 1 EMG
  
      # Test reading all conditions from evokeds
      evokeds = read_evokeds_mff(egi_mff_evoked_fname)
      assert len(evokeds) == 2
      # Test reading list of conditions from evokeds
      evokeds = read_evokeds_mff(egi_mff_evoked_fname, condition=[0, 1])
      assert len(evokeds) == 2
      # Test invalid condition
      with pytest.raises(ValueError) as exc_info:
          read_evokeds_mff(
              egi_mff_evoked_fname, condition="Invalid Condition"
          )
      message = (
          "Invalid value for the 'condition' parameter provided as "
          "category name. Allowed values are 'Category 1' and "
          "'Category 2', but got 'Invalid Condition' instead."
      )
      assert str(exc_info.value) == message
      with pytest.raises(ValueError) as exc_info:
          read_evokeds_mff(egi_mff_evoked_fname, condition=2)
      message = (
          '"condition" parameter (2), provided as epoch index, '
          "is out of range for available epochs (2)."
      )
      assert str(exc_info.value) == message
      with pytest.raises(TypeError) as exc_info:
          read_evokeds_mff(egi_mff_evoked_fname, condition=1.2)
      message = '"condition" parameter must be either int or str.'
      assert str(exc_info.value) == message
      # Test reading evoked data from single condition
      evoked_cond = read_evokeds_mff(
          egi_mff_evoked_fname, condition=cond
      )
      evoked_idx = read_evokeds_mff(egi_mff_evoked_fname, condition=idx)
      for evoked in [evoked_cond, evoked_idx]:
          assert evoked.comment == cond
          assert evoked.nave == 3
          assert evoked.tmin == 0.0
          assert evoked.tmax == tmax
      # Check signal data
      data = np.loadtxt(signals, ndmin=2).T * 1e-6  # convert to volts
      assert_allclose(evoked_cond.data, data, atol=1e-12)
      assert_allclose(evoked_idx.data, data, atol=1e-12)
      # Check info
      assert object_diff(evoked_cond.info, evoked_idx.info) == ""
      assert evoked_cond.info["description"] == cond
      assert evoked_cond.info["bads"] == bads
      assert (
          len(evoked_cond.info["ch_names"]) == n_eeg + n_ref + n_pns
      )  # 259
      assert "ECG" in evoked_cond.info["ch_names"]
      assert "EMG" in evoked_cond.info["ch_names"]
      assert "ecg" in evoked_cond
      assert "emg" in evoked_cond
      pick_eeg = pick_types(evoked_cond.info, eeg=True, exclude=[])
      assert len(pick_eeg) == n_eeg + n_ref  # 257
      assert evoked_cond.info["nchan"] == n_eeg + n_ref + n_pns  # 259
      assert evoked_cond.info["sfreq"] == 250.0
      assert not evoked_cond.info["custom_ref_applied"]
      assert len(evoked_cond.info["dig"]) == n_card + n_eeg + n_ref
      assert (
          evoked_cond.info["device_info"]["type"]
          == "HydroCel GSN 256 1.0"
      )
  
imports: import os
  import shutil
  from copy import deepcopy
  from datetime import datetime, timezone
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal
  from scipy import io
  from mne import find_events, pick_types
  from mne._fiff.constants import FIFF
  from mne.datasets.testing import data_path, requires_testing_data
  from mne.io import read_evokeds_mff, read_raw_egi, read_raw_fif
  from mne.io.egi.egi import _combine_triggers
  from mne.io.tests.test_raw import _test_raw_reader
  from mne.utils import object_diff
label_desc: Use image node_id 8 for calling a global function with example usage: test_io_egi_evokeds_mff(idx, cond, tmax, signals, bads) without return types