code: def test_ucb():
      assert np.allclose(crit.UCB(0, 1, 1), 1)
      assert np.allclose(crit.UCB(0, 1, 2), 2)
      assert np.allclose(crit.UCB(0, 4, 1), 2)
      assert np.allclose(crit.UCB(1, 4, 1), 3)
  
imports: import numpy
  import hyperopt.criteria
label_desc: Use image node_id 4 for calling a global function with example usage: test_ucb() without return types