code: def test_mixed_inputs(self):
      en = empirical_normalization.EmpiricalNormalization(7)
      for t in range(5):
          y = en(np.random.rand(t + 1, 7))
          self.assertIsInstance(y, np.ndarray)
          y = en(chainer.Variable(np.random.rand(t + 1, 7)))
          self.assertIsInstance(y, chainer.Variable)
  
file_path: chainerrl/tests/links_tests/test_empirical_normalization.py
imports: import unittest
  import chainer
  from chainer import testing
  import numpy
  from chainerrl.links import empirical_normalization
label_desc: Use image node_id 7 for calling the TestEmpiricalNormalization obj's underlying member method code with example usage: obj.test_mixed_inputs() without return types