code: def setUp(self):
      if self.dtype == numpy.float16:
          self.check_forward_options = {"atol": 1e-2, "rtol": 1e-2}
      else:
          self.check_forward_options = {"atol": 1e-4, "rtol": 1e-4}
      self.check_backward_options = {
          "eps": 1e-3,
          "atol": 5e-2,
          "rtol": 1e-3,
      }
      self.check_double_backward_options = {
          "eps": 1e-3,
          "atol": 5e-2,
          "rtol": 1e-3,
      }
  
file_path: chainer/tests/chainer_tests/functions_tests/math_tests/test_polygamma.py
imports: import unittest
  import numpy
  import chainer
  import chainer.functions
  from chainer import testing
label_desc: Use image node_id 1 for calling the TestPolyGamma obj's underlying member method code with example usage: obj.setUp() without return types