class_docstr: Swap-in HDF5 File Handler.
code: def _add_band_data_file_content(self):
      num_cols = self._num_cols_for_file_type
      num_scans = self.num_scans
      rows_per_scan = self._rows_per_scan
      is_mersi2 = self.filetype_info["file_type"].startswith("mersi2_")
      is_1km = "_1000" in self.filetype_info["file_type"]
      data_func = (
          _get_1km_data
          if is_1km
          else (_get_250m_data if is_mersi2 else _get_250m_ll_data)
      )
      return data_func(num_scans, rows_per_scan, num_cols)
  
imports: import os
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.tests.reader_tests.test_hdf5_utils import FakeHDF5FileHandler
label_desc: Use image node_id 6 for calling the FakeHDF5FileHandler2 obj's underlying member method code with example usage: obj._add_band_data_file_content() and returns: data_func