code: def test_poisson_predict_length():
      """
      Tests that the prediction dataframe length is equal to the number of steps h
      """
      model = pf.GAS(data=countdata, ar=2, sc=2, family=pf.Poisson())
      x = model.fit()
      x.summary()
      assert model.predict(h=5).shape[0] == 5
  
imports: import numpy
  import pyflux
label_desc: Use image node_id 10 for calling a global function with example usage: test_poisson_predict_length() without return types