code: def _read_nihon_metadata(fname):
      metadata = {}
      fname = _ensure_path(fname)
      pnt_fname = fname.with_suffix(".PNT")
      if not pnt_fname.exists():
          warn("No PNT file exists. Metadata will be blank")
          return metadata
      logger.info("Found PNT file, reading metadata.")
      with open(pnt_fname) as fid:
          version = np.fromfile(fid, "|S16", 1).astype("U16")[0]
          if version not in _valid_headers:
              raise ValueError(
                  f"Not a valid Nihon Kohden PNT file ({version})"
              )
          metadata["version"] = version
  
          # Read timestamp
          fid.seek(0x40)
          meas_str = np.fromfile(fid, "|S14", 1).astype("U14")[0]
          meas_date = datetime.strptime(meas_str, "%Y%m%d%H%M%S")
          meas_date = meas_date.replace(tzinfo=timezone.utc)
          metadata["meas_date"] = meas_date
  
      return metadata
  
imports: from collections import OrderedDict
  from datetime import datetime, timezone
  from pathlib import Path
  import numpy
  from ..._fiff.meas_info import create_info
  from ..._fiff.utils import _mult_cal_one
  from ...annotations import Annotations
  from ...utils import _check_fname, fill_doc, logger, verbose, warn
  from ..base import BaseRaw
label_desc: Use image node_id 3 for calling a global function with example usage: _read_nihon_metadata(fname) and returns: metadata, metadata