code: def test(self):
      def greedy_action_func():
          return np.asarray([0] * self.action_size, dtype=np.float32)
  
      if self.sigma_type == "scalar":
          sigma = np.random.rand()
      elif self.sigma_type == "ndarray":
          sigma = np.random.rand(self.action_size)
      theta = np.random.rand()
  
      explorer = AdditiveOU(theta=theta, sigma=sigma)
  
      print("theta:", theta, "sigma", sigma)
      for t in range(100):
          a = explorer.select_action(t, greedy_action_func)
          print(t, a)
  
imports: import unittest
  from chainer import testing
  import numpy
  from chainerrl.explorers.additive_ou import AdditiveOU
label_desc: Use image node_id 1 for calling the TestAdditiveOU obj's underlying member method code with example usage: obj.test() and returns: np