code: def setUp(self):
      if isinstance(self.alpha_range, tuple):
          l, u = self.alpha_range
          self.alpha = random.uniform(l, u)
      else:
          self.alpha = self.alpha_range
  
      if self.dtype == numpy.float16:
          self.check_forward_options.update(
              {"atol": 5e-4, "rtol": 5e-3}
          )
          self.check_backward_options.update(
              {"atol": 5e-4, "rtol": 5e-3}
          )
          self.check_double_backward_options.update(
              {"atol": 5e-4, "rtol": 5e-3}
          )
  
file_path: chainer/tests/chainer_tests/functions_tests/activation_tests/test_elu.py
imports: import random
  import numpy
  from chainer import functions
  from chainer import testing
label_desc: Use image node_id 1 for calling the TestELU obj's underlying member method code with example usage: obj.setUp() without return types