// to specify the absolute path to these files in a customized components.xml
        // file. Ideally, we'd do full pattern-evaluation against the sysprops, but this
        // is a first step. There are several replacements below, in order to normalize
        // the path character before we operate on the string as a regex input, and

        optimizer gives more control over different phases of optimizer calls,
        and is easier to customize. We provide Adam, SGD, Adadelta, AdaGrad and
        RMSprop optimizers based on
        `tf.keras.optimizers.experimental.Optimizer`. Generally the new
        optimizers work in the same way as the old ones, but support new
        constructor arguments. In the future, the symbols