code: def _hydrocel(basename, head_size):
      fname = op.join(MONTAGE_PATH, basename)
      return _read_sfp(fname, head_size)
  
imports: import csv
  import os.path
  from collections import OrderedDict
  from functools import partial
  import numpy
  from .._freesurfer import get_mni_fiducials
  from ..transforms import _sph_to_cart
  from ..utils import _pl, _soft_import, warn
  from .None import __file__
  from .montage import make_dig_montage
label_desc: Use image node_id 3 for calling a global function with example usage: _hydrocel(basename, head_size) and returns: _read_sfp