code: def coxph_smoke():
      heart = h2o.import_file(
          pyunit_utils.locate("smalldata/coxph_test/heart.csv")
      )
      coxph = H2OCoxProportionalHazardsEstimator(
          start_column="start", stop_column="stop"
      )
      coxph.train(x="age", y="event", training_frame=heart)
  
      assert coxph.model_id != ""
      assert coxph.formula() == "Surv(start, stop, event) ~ age", (
          "Expected formula to be 'Surv(start, stop, event) ~ age' but it was "
          + coxph.formula()
      )
  
      pred = coxph.predict(test_data=heart)
      assert len(pred) == len(heart)
  
imports: import sys
  import h2o
  from tests import pyunit_utils
  from h2o.estimators.coxph import H2OCoxProportionalHazardsEstimator
label_desc: Use image node_id 1 for calling a global function with example usage: coxph_smoke() without return types