code: def test_frequency_range_channel_containment():
      """Test the frequency range object: channel containment."""
      frqr = FrequencyRange(2, 1)
      assert 1.7 in frqr
      assert 2.8 not in frqr
  
      with pytest.raises(NotImplementedError):
          assert frqr in FrequencyRange(89, 2, "MHz")
  
      frqr = None
      assert (frqr in FrequencyRange(89, 2)) is False
  
      assert "89" not in FrequencyRange(89, 2)
  
imports: import unittest
  from datetime import datetime
  import numpy
  import pytest
  from satpy.dataset.dataid import DataID, DataQuery, ModifierTuple, WavelengthRange, minimal_default_keys_config
  from satpy.readers.pmw_channels_definitions import FrequencyDoubleSideBand, FrequencyQuadrupleSideBand, FrequencyRange
  from satpy.tests.utils import make_cid, make_dataid, make_dsq
label_desc: Use image node_id 21 for calling a global function with example usage: test_frequency_range_channel_containment() without return types