code: public static <V> Action1<TaskContext<V>> exponentialWait(long initTime, TimeUnit timeUnit) {
          return exponentialWait(initTime, Long.MAX_VALUE, timeUnit);
      }
docs: The exponential increase sleep time.
  
  @param initTime The first sleep time.
  @param timeUnit The time unit.
  @param <V>      The return value type.
  @return The wait strategy action.