code: def setUp(self):
      self.check_forward_options.update({"atol": 1e-7, "rtol": 1e-7})
  
file_path: chainer/tests/chainer_tests/functions_tests/math_tests/test_sign.py
imports: import numpy
  from chainer import functions
  from chainer import testing
  from chainer import utils
label_desc: Use image node_id 1 for calling the TestSign obj's underlying member method code with example usage: obj.setUp() without return types