code: def test_graph_length(self):
      network = layers.join(
          layers.Input(10),
          layers.Relu(3),
      )
      self.assertEqual(2, len(network))
  
      network_2 = layers.join(
          network,
          layers.parallel(
              layers.Relu(1),
              layers.Relu(2),
          ),
      )
      self.assertEqual(2, len(network))
      self.assertEqual(4, len(network_2))
  
file_path: neupy/tests/layers/graph/test_usage.py
imports: import numpy
  from neupy import layers
  from neupy.utils import asfloat
  from base import BaseTestCase
label_desc: Use image node_id 7 for calling the UsageTestCase obj's underlying member method code with example usage: obj.test_graph_length() without return types