* minimizes the size of the subranges from which the remaining selections must be done.
   */
  private static int chooseNextSelection(
      int[] allRequired, int requiredFrom, int requiredTo, int from, int to) {
    if (requiredFrom == requiredTo) {
      return requiredFrom; // only one thing to choose, so choose it
    }

    // Find the center and round down. The true center is either centerFloor or halfway between

        @jakarta.validation.constraints.NotNull
        @CronExpression
        private String requiredCron;

        public String getRequiredCron() {
            return requiredCron;
        }

        public void setRequiredCron(String requiredCron) {
            this.requiredCron = requiredCron;
        }
    }

    @CronExpression
    @jakarta.validation.constraints.NotBlank