@NonNull
    public static <T> List<Handler<T>> unwraps(@Nullable Collection<? extends Handler<T>> tasks) {
        if (tasks == null) {
            return Collections.emptyList();
        }

        List<Handler<T>> copy = new ArrayList<>();
        for (Handler<T> task : tasks) {
            if (!(task instanceof TtlVertxHandler)) {
                copy.add(task);
            } else {
                copy.add(((TtlVertxHandler<T>) task).getHandler());
            }
        }
        return copy;
    }
Unwrap {@link TtlVertxHandler} to the original/underneath one for collection.
<p>
Invoke {@link #unwrap(Handler)} for each element in input collection.
<p>
This method is {@code null}-safe, when input {@code Handler} parameter collection is {@code null}, return a empty list.

@see #gets(Collection)
@see #unwrap(Handler)
ttl-integrations/vertx4-ttl-integration/src/main/java/com/alibaba/ttl/integration/vertx4/TtlVertxHandler.java