The example "get_formations.py" run into error of "no compute_formation()"

[aijcode]

When the code get_formations.py in the examples was run, it failed with the error "no compute_formation()". I want to calculate the formation energy and get the key of "description". I find the functions of calculate_stability(), compute_formation_energies() , get_formation() and formation_energy(), but none of them calculates formation energy but just reads the database or do something others. So, how to calculate the formation energy with qmpy?