class_docstr: Writer class of fake mws level-1b data.
docstr: Write the calibration data group.
docstr_tok: ["Write","the","calibration","data","group","."]
code: def _write_calibration_data_group(dataset):
      """Write the calibration data group."""
      group = dataset.createGroup("calibration")
      toa_bt = group.createVariable(
          "mws_toa_brightness_temperature",
          np.float32,
          dimensions=(
              "n_scans",
              "n_fovs",
              "n_channels",
          ),
      )
      toa_bt.scale_factor = 1.0  # 1.0E-8
      toa_bt.add_offset = 0.0
      toa_bt.missing_value = -2147483648
      toa_bt[:] = 240.0 * np.ones((N_SCANS, N_FOVS, N_CHANNELS))
  
imports: import logging
  from datetime import datetime
  from unittest.mock import patch
  import numpy
  import pytest
  import xarray
  from netCDF4 import Dataset
  from satpy.readers.mws_l1b import MWSL1BFile, get_channel_index_from_name
label_desc: Use image node_id 8 for calling the MWSL1BFakeFileWriter obj's underlying member method code with example usage: obj._write_calibration_data_group(dataset) without return types