code: def _get_timeunit_scaling(time_unit):
      """MNE expects time in seconds, return required scaling."""
      scalings = {"ms": 1000, "s": 1, "unknown": 1}
      if time_unit in scalings:
          return scalings[time_unit]
      else:
          raise RuntimeError(
              f"The time unit {time_unit} is not supported by "
              "MNE. Please report this error as a GitHub "
              "issue to inform the developers."
          )
  
imports: import datetime
  import re
  import numpy
  from ..._fiff._digitization import _make_dig_points
  from ..._fiff.constants import FIFF
  from ..._fiff.meas_info import _format_dig_points, create_info
  from ..._fiff.utils import _mult_cal_one
  from ..._freesurfer import get_mni_fiducials
  from ...annotations import Annotations
  from ...transforms import _frame_to_str, apply_trans
  from ...utils import _check_fname, _import_h5py, fill_doc, logger, verbose, warn
  from ..base import BaseRaw
  from ..nirx.nirx import _convert_fnirs_to_head
label_desc: Use image node_id 4 for calling a global function with example usage: _get_timeunit_scaling(time_unit) and returns: scalings