code: def _mult_cal_one(data_view, one, idx, cals, mult):
      """Take a chunk of raw data, multiply by mult or cals, and store."""
      one = np.asarray(one, dtype=data_view.dtype)
      assert data_view.shape[1] == one.shape[1], (
          data_view.shape[1],
          one.shape[1],
      )  # noqa: E501
      if mult is not None:
          assert mult.ndim == one.ndim == 2
          data_view[:] = mult @ one[idx]
      else:
          assert cals is not None
          if isinstance(idx, slice):
              data_view[:] = one[idx]
          else:
              # faster than doing one = one[idx]
              np.take(one, idx, axis=0, out=data_view)
          data_view *= cals
  
file_path: mne-python/mne/_fiff/utils.py
imports: import os
  import os.path
  import numpy
  from .constants import FIFF
  from .meas_info import _get_valid_units
label_desc: Use image node_id 3 for calling a global function with example usage: _mult_cal_one(data_view, one, idx, cals, mult) without return types