code: def testBiasOnly_BreaksDownLayerWeights(self):
      model = _build_model()
  
      first_conv_layer = model.layers[2]
      self.assertLen(first_conv_layer.weights, 2)
  
      compressed_model = bias_only.BiasOnly().compress_model(model)
  
      first_conv_layer = compressed_model.layers[2]
  
      self.assertLen(first_conv_layer.weights, 3)
  
file_path: model-optimization/tensorflow_model_optimization/python/core/common/keras/compression/algorithms/bias_only_test.py
imports: import os
  import tempfile
  import tensorflow
  from tensorflow_model_optimization.python.core.common.keras.compression.algorithms import bias_only
  from tensorflow_model_optimization.python.core.keras.testing import test_utils_mnist
label_desc: Use image node_id 4 for calling the FunctionalTest obj's underlying member method code with example usage: obj.testBiasOnly_BreaksDownLayerWeights() without return types