code: def test_sigmoid(self, seed):
      np.random.seed(seed)
      opname = "Sigmoid"
      regions = [
          [-8.0, -4.0],
          [-4.0, -2.0],
          [-2.0, -1.0],
          [-1.0, -0.5],
          [-0.5, -0.25],
          [-0.25, 0.25],
          [0.25, 0.5],
          [0.5, 1.0],
          [1.0, 2.0],
          [2.0, 4.0],
          [4.0, 8.0],
      ]
      self._test_op_w_ulp_error(
          seed, opname, regions, atol=0, err_threshold=2.5
      )
  
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 UnaryOpTest obj's underlying member method code with example usage: obj.test_sigmoid(seed) without return types