code: def _read_ustring(fid, n_bytes):
      """Read unsigned character string."""
      return np.fromfile(fid, ">B", n_bytes)
  
file_path: mne-python/mne/io/ctf/res4.py
imports: import os.path
  import numpy
  from ...utils import logger
  from .constants import CTF
label_desc: Use image node_id 4 for calling a global function with example usage: _read_ustring(fid, n_bytes) and returns: np