code: def forward(self, inputs, device):
      if self.test_partial:
          e1, e2, W = inputs
          V1 = None
          V2 = None
          b = None
      else:
          e1, e2, W, V1, V2, b = inputs
      flags = V1 is None, V2 is None, b is None
      if any(flags):
          if not all(flags):
              raise ValueError(
                  "Test either all or none of the optional parameters."
              )
          y = functions.bilinear(e1, e2, W)
      else:
          y = functions.bilinear(e1, e2, W, V1, V2, b)
      return (y,)
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 4 for calling the TestBilinearFunction obj's underlying member method code with example usage: obj.forward(inputs, device) and returns: y