code: @Nonnull
      public static <T> List<Callable<T>> unwraps(@Nullable Collection<? extends Callable<T>> tasks) {
          if (null == tasks) return Collections.emptyList();
  
          List<Callable<T>> copy = new ArrayList<Callable<T>>();
          for (Callable<T> task : tasks) {
              if (!(task instanceof TtlCallable)) copy.add(task);
              else copy.add(((TtlCallable<T>) task).getCallable());
          }
          return copy;
      }
docs: Unwrap {@link TtlCallable} to the original/underneath one.
  <p>
  Invoke {@link #unwrap(Callable)} for each element in input collection.
  <p>
  This method is {@code null}-safe, when input {@code Callable} parameter is {@code null}, return a empty list.
  
  @see #gets(Collection)
  @see #unwrap(Callable)
  @since 2.10.2