code: def check_backward(self, inputs_data, output_grad, atol, rtol):
      gradient_check.check_backward(
          self.op,
          inputs_data,
          output_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 7 for calling the TestEinSum obj's underlying member method code with example usage: obj.check_backward(inputs_data, output_grad, atol, rtol) without return types