code: def setUp(self):
      self.xs = [
          numpy.random.uniform(-1, 1, (l,) + self.shape).astype(
              self.dtype
          )
          for l in self.lengths
      ]
      self.ggxs = [
          numpy.random.uniform(-1, 1, (l,) + self.shape).astype(
              self.dtype
          )
          for l in self.lengths
      ]
  
      if self.length == "max":
          self.length = max(self.lengths)
  
      if self.length:
          max_length = self.length
      else:
          max_length = max(self.lengths)
      self.y_shape = (
          len(self.lengths),
          max_length,
      ) + self.shape
      self.gy = numpy.random.uniform(-1, 1, self.y_shape).astype(
          self.dtype
      )
  
      self.check_double_backward_options = {"atol": 5e-4, "rtol": 5e-3}
      if self.dtype == numpy.float16:
          self.check_double_backward_options.update({"atol": 5e-3})
  
      self.can_include_nan = numpy.isnan(self.pad)
  
imports: import contextlib
  import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 1 for calling the TestPadSequence obj's underlying member method code with example usage: obj.setUp() without return types