code: def infer_shape(self, node, i0_shapes):
      return [i0_shapes[0], i0_shapes[0]]
  
imports: from __future__ import absolute_import, print_function, division
  import unittest
  import theano
  import numpy
  from theano.gof import Op, Apply
  from theano import tensor, function, printing
  from theano.tests import unittest_tools
  import theano
  import numpy
  from theano.compile.ops import as_op
label_desc: Use image node_id 6 for calling the SumDiffOp obj's underlying member method code with example usage: obj.infer_shape(node, i0_shapes) and returns: list