code: def test_layer_type_filter(self):
      mm = (
          ManifoldMixup()
          .at_depth(None)
          .with_layer_type_filter([nn.Conv1d])
      )
      state = {torchbearer.MODEL: self.model}
      mm.on_start(state)
  
      self.assertFalse(
          self.model.conv1 in mm._layers,
          self.model.layer1.conv in mm._layers
          and self.model.layer2.layer1.conv in mm._layers,
      )
      self.assertTrue(len(mm._layers) == 12 - 3)
  
imports: from unittest import TestCase
  from mock import patch, Mock
  from torch import nn
  from torchbearer.callbacks.manifold_mixup import ManifoldMixup
  import torchbearer
  import torch
label_desc: Use image node_id 9 for calling the TestManifoldMixup obj's underlying member method code with example usage: obj.test_layer_type_filter() without return types