default <V> ThrowingFunction<T, V, E> andThen(ThrowingFunction<? super R, ? extends V, ? extends E> after) {
        Objects.requireNonNull(after);
        return (T t) -> after.apply(apply(t));
    }
Functional interface that mirrors the Function interface, but allows for an
exception to be thrown.

@author oyving
vespajlib/src/main/java/com/yahoo/yolean/function/ThrowingFunction.java