code: def test_forward_gpu(self):
      self.check_forward(
          cuda.to_gpu(self.a), cuda.to_gpu(self.p), cuda.to_gpu(self.n)
      )
  
imports: import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 5 for calling the TestTriplet obj's underlying member method code with example usage: obj.test_forward_gpu() without return types