class_docstr: Test the SAFE XML Calibration file handler.
class_docstr_tok: ["Test","the","SAFE","XML","Calibration","file","handler","."]
docstr: Test reading the sigma calibration array.
docstr_tok: ["Test","reading","the","sigma","calibration","array","."]
code: def test_sigma_calibration_array(self):
      """Test reading the sigma calibration array."""
      expected_sigma = np.array(
          [
              [
                  1894.274,
                  1841.4335,
                  1788.593,
                  1554.4165,
                  1320.24,
                  1299.104,
                  1277.968,
                  1277.968,
                  1277.968,
                  1277.968,
              ]
          ]
      ) * np.ones((10, 1))
      res = self.calibration_fh.get_calibration(
          Calibration.sigma_nought, chunks=5
      )
      np.testing.assert_allclose(res, expected_sigma)
  
imports: import unittest
  import unittest.mock
  from enum import Enum
  from io import BytesIO
  import dask.array
  import numpy
  import xarray
  from satpy.dataset import DataQuery
  from satpy.readers.sar_c_safe import SAFEXMLAnnotation, SAFEXMLCalibration, SAFEXMLNoise
label_desc: Use image node_id 4 for calling the TestSAFEXMLCalibration obj's underlying member method code with example usage: obj.test_sigma_calibration_array() without return types