public static interface Composition.FunctionComposition<T,R>
<S> Function<S,R>
after(Function<S,T> before)
<S> Function<T,S>
andThen(Function<R,S> then)
<S> Function<T,S> andThen(Function<R,S> then)
<S> Function<S,R> after(Function<S,T> before)