code: def test_rng_reserve_size(self):
      cfg = config.get_config()
      prev = config.rng_reserve_size(3)
      self.assertEqual(cfg.rng_reserve_size, 3)
      self.assertEqual(prev, 1)
      prev = config.rng_reserve_size(10)
      self.assertEqual(cfg.rng_reserve_size, 10)
      self.assertEqual(prev, 3)
  
imports: from concurrent import futures
  import inspect
  import threading
  from absl.testing import absltest
  from absl.testing import parameterized
  from haiku._src import config
label_desc: Use image node_id 11 for calling the ConfigTest obj's underlying member method code with example usage: obj.test_rng_reserve_size() without return types