code: def _check(self):
      r = self.r if self.specify_r else None
      return_r = self.return_r
      with chainer.using_config("train", self.train):
          out = functions.rrelu(
              self.x, self.l, self.u, r=r, return_r=return_r
          )
  
      if not return_r:
          return
  
      out, out_r = out
      assert isinstance(out_r, type(out.array))
      if r is None:
          assert out_r.shape == out.array.shape
      else:
          if self.train:
              assert out_r is r
  
file_path: chainer/tests/chainer_tests/functions_tests/activation_tests/test_rrelu.py
imports: import unittest
  import numpy
  import chainer
  from chainer import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 2 for calling the TestRReLUR obj's underlying member method code with example usage: obj._check() without return types