code: public static IterativePollInterval iterative(Function<Duration, Duration> function, Duration startDuration) {
          return new IterativePollInterval(function, startDuration);
      }
docs: Syntactic sugar for creating a {@link IterativePollInterval}.
  
  @param function      The function to use
  @param startDuration The start duration (initial function value)
  @return A new instance of {@link IterativePollInterval}