class_docstr: Test the area helpers.
docstr: Test the retrieval of user-supplied calibration factors.
code: def test_get_user_calibration_factors(self):
      """Test the retrieval of user-supplied calibration factors."""
      radcor_dict = {
          "WV063": {"slope": 1.015, "offset": -0.0556},
          "IR108": {"slo": 1.015, "off": -0.0556},
      }
      # Test that correct values are returned from the dict
      slope, offset = hf.get_user_calibration_factors(
          "WV063", radcor_dict
      )
      assert slope == 1.015
      assert offset == -0.0556
  
      # Test that channels not present in dict return 1.0, 0.0
      with self.assertWarns(UserWarning):
          slope, offset = hf.get_user_calibration_factors(
              "IR097", radcor_dict
          )
      assert slope == 1.0
      assert offset == 0.0
  
      # Check that incorrect dict keys throw an error
      with pytest.raises(KeyError):
          hf.get_user_calibration_factors("IR108", radcor_dict)
  
imports: import os
  import unittest
  from datetime import datetime
  from unittest import mock
  import dask.array
  import numpy
  import numpy.testing
  import pyresample.geometry
  import pytest
  import xarray
  from fsspec.implementations.memory import MemoryFile, MemoryFileSystem
  from pyproj import CRS
  from satpy.readers import FSFile
  from satpy.readers import utils
label_desc: Use image node_id 16 for calling the TestHelpers obj's underlying member method code with example usage: obj.test_get_user_calibration_factors() without return types