code: public ZoneRulesBuilder addRuleToWindow(
              LocalDateTime transitionDateTime,
              TimeDefinition timeDefinition,
              int savingAmountSecs) {
          Jdk8Methods.requireNonNull(transitionDateTime, "transitionDateTime");
          return addRuleToWindow(
                  transitionDateTime.getYear(), transitionDateTime.getYear(),
                  transitionDateTime.getMonth(), transitionDateTime.getDayOfMonth(),
                  null, transitionDateTime.toLocalTime(), false, timeDefinition, savingAmountSecs);
      }
docs: Adds a single transition rule to the current window.
  <p>
  This adds a rule such that the offset, expressed as a daylight savings amount,
  changes at the specified date-time.
  
  @param transitionDateTime  the date-time that the transition occurs as defined by timeDefintion, not null
  @param timeDefinition  the definition of how to convert local to actual time, not null
  @param savingAmountSecs  the amount of saving from the standard offset after the transition in seconds
  @return this, for chaining
  @throws IllegalStateException if no window has yet been added
  @throws IllegalStateException if the window already has fixed savings
  @throws IllegalStateException if the window has reached the maximum capacity of 2000 rules