code: def test_multi_inputs_propagation(self):
      network = layers.join(
          layers.parallel(
              layers.Input(10, name="input-1"),
              layers.Input(4, name="input-2"),
          ),
          layers.Concatenate(),
      )
      x1 = asfloat(np.random.random((3, 10)))
      x2 = asfloat(np.random.random((3, 4)))
  
      out1 = self.eval(network.output(x1, x2))
      out2 = self.eval(network.output({"input-2": x2, "input-1": x1}))
  
      self.assertEqual((3, 14), out1.shape)
      np.testing.assert_array_almost_equal(out1, out2)
  
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 3 for calling the UsageTestCase obj's underlying member method code with example usage: obj.test_multi_inputs_propagation() without return types