code: def test_void(self):
      btc_spctr = NeuralType(("B", "T", "C"), SpectrogramType())
      btc_spct_bad = NeuralType(("B", "T"), SpectrogramType())
      btc_void = NeuralType(("B", "T", "C"), VoidType())
  
      assert (
          btc_void.compare(btc_spctr) == NeuralTypeComparisonResult.SAME
      )
      assert (
          btc_spctr.compare(btc_void)
          == NeuralTypeComparisonResult.INCOMPATIBLE
      )
      assert (
          btc_void.compare(btc_spct_bad)
          == NeuralTypeComparisonResult.INCOMPATIBLE
      )
  
file_path: NeMo/tests/core/test_neural_types.py
imports: import pytest
  from nemo.core.neural_types import AcousticEncodedRepresentation, AudioSignal, AxisKind, AxisKindAbstract, AxisType, ChannelType, ElementType, MelSpectrogramType, MFCCSpectrogramType, NeuralType, NeuralTypeComparisonResult, SpectrogramType, VoidType
label_desc: Use image node_id 8 for calling the TestNeuralTypeSystem obj's underlying member method code with example usage: obj.test_void() without return types