code: def check_double_backward(
      self, x1_data, x2_data, y_grad, x1_grad_grad, x2_grad_grad
  ):
      gradient_check.check_double_backward(
          F.arctan2,
          (x1_data, x2_data),
          y_grad,
          (x1_grad_grad, x2_grad_grad),
          dtype="d",
          **self.double_backward_options,
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  import chainer.functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 8 for calling the TestArctan2 obj's underlying member method code with example usage: obj.check_double_backward(x1_data, x2_data, y_grad, x1_grad_grad, x2_grad_grad) without return types