code: def _get_calibration(num_scans):
      calibration = {
          "Calibration/VIS_Cal_Coeff": xr.DataArray(
              da.ones((19, 3), chunks=1024),
              attrs={
                  "Slope": np.array([1.0] * 19),
                  "Intercept": np.array([0.0] * 19),
              },
              dims=("_bands", "_coeffs"),
          ),
          "Calibration/IR_Cal_Coeff": xr.DataArray(
              da.ones((6, 4, num_scans), chunks=1024),
              attrs={
                  "Slope": np.array([1.0] * 6),
                  "Intercept": np.array([0.0] * 6),
              },
              dims=("_bands", "_coeffs", "_scans"),
          ),
      }
      return calibration
  
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 1 for calling a global function with example usage: _get_calibration(num_scans) and returns: calibration