Let's say I have written a `NetChain` machine learning setup, trained the chain with `NetTrain` and obtained a model ready to predict:

    model = NetChain[...];
    trained = NetTrain[model,...];

The whole process took a long time to prepare, so I do not want to repeat the same preparation steps the next time I start Mathematica. Is there a way to save `trained` and load from memory instead of recreating it?