code: def test_use_bias_false(self):
      layer = tl.Conv(30, (3, 3), use_bias=False)
      x = np.ones((9, 5, 5, 20))
      layer.init(shapes.signature(x))
  
      y = layer(x)
      self.assertEqual(y.shape, (9, 3, 3, 30))
      # With use_bias=False, layer.weights is just 'w' and there is no 'b'.
      self.assertEqual(layer.weights.shape, (3, 3, 20, 30))
  
file_path: trax/trax/layers/convolution_test.py
imports: from absl.testing import absltest
  import numpy
  from trax import shapes
  import trax.layers
label_desc: Use image node_id 3 for calling the ConvolutionTest obj's underlying member method code with example usage: obj.test_use_bias_false() without return types