class_docstr: Unit tests for the slope of Meirink calibration.
docstr: Test the value of the slope of the Meirink calibration.
docstr_tok: ["Test","the","value","of","the","slope","of","the","Meirink","calibration","."]
code: def test_get_meirink_slope_2020(self, platform_id, time, expected):
      """Test the value of the slope of the Meirink calibration."""
      coefs = {"coefs": {}}
      coefs["coefs"]["NOMINAL"] = {"gain": -1, "offset": -1}
      coefs["coefs"]["EXTERNAL"] = {}
      for i, channel_name in enumerate(["VIS006", "VIS008", "IR_016"]):
          calibration_handler = SEVIRICalibrationHandler(
              platform_id, channel_name, coefs, "MEIRINK-2023", time
          )
          assert (
              abs(
                  calibration_handler.get_gain_offset()[0] - expected[i]
              )
              < 1e-6
          )
  
imports: import unittest
  from datetime import datetime, timedelta
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.readers.seviri_base import MEIRINK_COEFS, MEIRINK_EPOCH, NoValidOrbitParams, OrbitPolynomial, OrbitPolynomialFinder, SEVIRICalibrationHandler, chebyshev, dec10216, get_cds_time, get_padding_area, get_satpos, pad_data_horizontally, pad_data_vertically, round_nom_time
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 2 for calling the TestMeirinkSlope obj's underlying member method code with example usage: obj.test_get_meirink_slope_2020(platform_id, time, expected) without return types