def _getscreen():
    if Turtle._screen is None:
        Turtle._screen = Screen()
    return Turtle._screen
when the clipped input is multiplied by the normalisation mask, the normalisation denominators are generated.
dataset/ETHPy150Open amrdraz/kodr/app/brython/www/src/Lib/site-packages/turtle.py/_getscreen--crossover with--dataset/ETHPy150Open benanne/kaggle-galaxies/custom.py/OptimisedDivGalaxyOutputLayer.generate_normalisation_mask