public static <T, R> Callable<R> andThen(Callable<T> callable, Function<T, R> resultHandler){
        return () -> resultHandler.apply(callable.call());
    }
public static < T , R > Callable < R > andThen ( Callable < T > callable , Function < T , R > resultHandler ) { return ( ) -> resultHandler . apply ( callable . call ( ) ) ; }
Returns a composed function that first applies the Callable and then applies
the resultHandler.

@param <T> return type of callable
@param <R> return type of handler
@param resultHandler the function applied after callable
@return a function composed of supplier and resultHandler