code: def setUp(self):
      self._config_user = chainer.using_config("dtype", self.dtype)
      self._config_user.__enter__()
  
      tree = ((0, 1), ((2, 3), 4))
      self.link = links.BinaryHierarchicalSoftmax(3, tree)
      self.link.cleargrads()
      self.x = numpy.random.uniform(-1, 1, (2, 3)).astype(self.dtype)
      self.t = numpy.array([0, 2]).astype(numpy.int32)
      self.gy = numpy.random.uniform(-1, 1, ()).astype(self.dtype)
  
      self.W = self.link.W.data.copy()
  
      if self.dtype == numpy.float16:
          self.check_sum_options = {"delta": 1e-3}
          self.test_forward_options = {"atol": 0.005}
          self.check_backward_options = {"dtype": numpy.float64}
      else:
          self.check_sum_options = {"delta": 1e-5}
          self.test_forward_options = {}
          self.check_backward_options = {}
  
imports: import copy
  import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import gradient_check
  from chainer import links
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
label_desc: Use image node_id 1 for calling the TestBinaryHierarchicalSoftmax obj's underlying member method code with example usage: obj.setUp() without return types