code: def test_rmse():
      """[Metrics] rmse."""
      z = metrics.rmse(y, p)
      np.testing.assert_equal(np.array(z), np.array(4.5276925690687087))
  
imports: import numpy
  from mlens import metrics
label_desc: Use image node_id 1 for calling a global function with example usage: test_rmse() without return types