code: def test_collect_variables(self):
      vs = chainerrl.misc.collect_variables(self.obj)
      self._assert_eq_var_list(vs, self.expected)
  
      # Wrap by a list
      vs = chainerrl.misc.collect_variables([self.obj])
      self._assert_eq_var_list(vs, self.expected)
  
      # Wrap by two lists
      vs = chainerrl.misc.collect_variables([[self.obj]])
      self._assert_eq_var_list(vs, self.expected)
  
      # Wrap by a tuple
      vs = chainerrl.misc.collect_variables((self.obj,))
      self._assert_eq_var_list(vs, self.expected)
  
      # Wrap by a two tuples
      vs = chainerrl.misc.collect_variables(((self.obj,),))
      self._assert_eq_var_list(vs, self.expected)
  
file_path: chainerrl/tests/misc_tests/test_draw_computational_graph.py
imports: import os
  import tempfile
  import unittest
  import chainer
  from chainer import testing
  import numpy
  import chainerrl
label_desc: Use image node_id 2 for calling the TestCollectVariables obj's underlying member method code with example usage: obj.test_collect_variables() without return types