docs: public static void validateMaintenanceSchedule(final String cronSchedule, final String duration,
              final String timezone) {
          if (allNotEmpty(cronSchedule, duration, timezone)) {
              validateCronSchedule(cronSchedule);
              validateDuration(duration);
              // check if there is a window currently active or available in
              // future.
              if (!getNextMaintenanceWindow(cronSchedule, duration, timezone).isPresent()) {
                  throw new InvalidMaintenanceScheduleException(
                          "No valid maintenance window available after current time");
              }
          } else if (atLeastOneNotEmpty(cronSchedule, duration, timezone)) {
              throw new InvalidMaintenanceScheduleException(
                      "All of schedule, duration and timezone should either be null or non empty.");
          }
      }