code: @SuppressWarnings("deprecation")
    private static <T> Task<T> vaseq(final Task<?>... tasks) {
      return new SeqTask<T>("seq", Arrays.asList(tasks));
    }
docs: Creates a new task that will run the given array of tasks sequentially
  (e.g. tasks[0] will be finished before tasks[1] is run). <strong>This
  method is not type-safe</strong> - prefer one of the {@code seq} options
  when possible. The value of this new task is the value of the last task in
  the sequence.
  
  @param tasks the tasks to run sequentially
  @param <T> the result value for the sequence of tasks
  @return a new task that will run the given tasks sequentially