code: def test_SPDN_sparse_matmul_double_backward_gpu(self):
      self.check_SPDN_double_backward(
          cuda.to_gpu(self.a),
          cuda.to_gpu(self.b),
          cuda.to_gpu(self.gc),
          cuda.to_gpu(self.gga),
          cuda.to_gpu(self.ggb),
          atol=1e-2,
          rtol=1e-2,
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer import cuda
  import chainer.functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 12 for calling the TestCooMatMul obj's underlying member method code with example usage: obj.test_SPDN_sparse_matmul_double_backward_gpu() without return types