code: def setUp(self):
      self.check_forward_options = {"atol": 1e-4, "rtol": 1e-5}
      if (
          self.x1_dtype == numpy.float16
          or self.x2_dtype == numpy.float16
      ):
          self.check_forward_options = {"atol": 2e-3, "rtol": 2e-3}
          self.check_double_backward_options = {
              "atol": 1e-2,
              "rtol": 1e-2,
          }
          self.check_backward_options = {"atol": 1e-2, "rtol": 1e-2}
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backend import CpuDevice
  import chainer.functions
  from chainer import testing
  from chainer.utils import type_check
label_desc: Use image node_id 1 for calling the TestMatMul obj's underlying member method code with example usage: obj.setUp() without return types