code: def check_double_backward(
      self, inputs_data, y_grad, inputs_grad_grad, atol, rtol
  ):
      gradient_check.check_double_backward(
          self.op,
          inputs_data,
          y_grad,
          inputs_grad_grad,
          atol=atol,
          rtol=rtol,
          dtype=numpy.float64,
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer.functions.math import einsum
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer import utils
label_desc: Use image node_id 6 for calling the TestDiagEinSum obj's underlying member method code with example usage: obj.check_double_backward(inputs_data, y_grad, inputs_grad_grad, atol, rtol) without return types