Concurrent Work Executor.java

public interface ConcurrentWorkExecutor {
 
    /**
     * Splits a work iterable and submits each task into an executor where the task input is obtained by
     * applying a mapper function. The intermediate non null results are joined until a {@code size} number
     * of results are obtained post which they are collected using a custom user defined collector.
     *
     * @param size      the number of results to wait for
     * @param iterable  the work represented as an iterable
     * @param mapper    the transformation of individual item U within the iterable to a result T
     * @param collector the collection of T results obtained into a custom collector of type V
     * @return an object of type V which is obtained after collection of intermediate T type results
     * @implNote - If all intermediate results are required before collecting the final result, {@code size}
     * must be equal to the number of items represented by the iterable
     */
    <T, U, V> V splitJoin(int size,
                          Iterable<U> iterable, 
                          Function<U, T> mapper,
                          Collector<T, ?, V> collector
                         ) throws ExecutionException, InterruptedException;
}