code: def test_sub_graph(self, seed):
      self._test_binary_op_graph("Sub", seed)
  
imports: import numpy
  import caffe2.python.fakelowp.init_shared_libs
  import datetime
  from hypothesis import given, settings
  from hypothesis import strategies
  from caffe2.proto import caffe2_pb2
  from caffe2.python import core
  from caffe2.python import workspace
  from caffe2.python.onnx.onnxifi import onnxifi_caffe2_net
  from caffe2.python.fakelowp.test_utils import print_test_debug_info
  from caffe2.python.fakelowp.test_utils import compute_ulp_error
  import caffe2.python.serialized_test.serialized_test_util
label_desc: Use image node_id 3 for calling the ArithmeticOpsTest obj's underlying member method code with example usage: obj.test_sub_graph(seed) without return types