code: def test_annot_noop(meas_date, first_samp, set_meas_date):
      """Show some unintuitive behavior of annotations."""
      sfreq = 1000.0
      info = create_info(1, sfreq, "eeg")
      onset = 0.5
      annot_kwargs = dict()
      if set_meas_date == "before":
          with info._unlock():
              info["meas_date"] = _handle_meas_date(meas_date)
          if meas_date is not None:
              onset += first_samp / sfreq
          annot_kwargs["orig_time"] = meas_date
      raw = RawArray(np.zeros((1, 2000)), info, first_samp=first_samp)
      annot = Annotations(onset, 0.1, "bad", **annot_kwargs)
      raw.set_annotations(annot, verbose="debug")
      if set_meas_date == "after":
          raw.set_meas_date(meas_date)
      first_annot = raw.annotations
      if meas_date is None:
          first_annot.onset -= raw.first_time
      raw.set_annotations(
          first_annot, verbose="debug"
      )  # should be a no-op...
      second_annot = raw.annotations
      want = first_annot.onset[0]
      # it has been shifted when meas_date is None!
      if meas_date is None:
          want = want + raw.first_time
      assert_allclose(second_annot.onset[0], want)
  
imports: import sys
  from collections import OrderedDict
  from datetime import datetime, timedelta, timezone
  from itertools import repeat
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_almost_equal, assert_array_equal, assert_equal
  from pytest import approx
  import mne
  from mne import Annotations, Epochs, annotations_from_events, count_annotations, create_info, events_from_annotations, read_annotations
  from mne.annotations import _handle_meas_date, _read_annotations_txt_parse_header, _sync_onset
  from mne.datasets import testing
  from mne.io import RawArray, concatenate_raws, read_raw_fif
  from mne.utils import _dt_to_stamp, _raw_annot, _record_warnings, _stamp_to_dt, assert_and_remove_boundary_annot, catch_logging, check_version
label_desc: Use image node_id 47 for calling a global function with example usage: test_annot_noop(meas_date, first_samp, set_meas_date) without return types