code: function(time) {
        if (!this.rangeExceptions.length) {
          return null;
        }
  
        var utc = time.toUnixTime();
        var idx = ICAL.helpers.binsearchInsert(
          this.rangeExceptions,
          [utc],
          compareRangeException
        );
  
        idx -= 1;
  
        // occurs before
        if (idx < 0) {
          return null;
        }
  
        var rangeItem = this.rangeExceptions[idx];
  
        /* istanbul ignore next: sanity check only */
        if (utc < rangeItem[0]) {
          return null;
        }
  
        return rangeItem[1];
      }
docs: Finds the range exception nearest to the given date.
  
  @param {ICAL.Time} time usually an occurrence time of an event
  @return {?ICAL.Event} the related event/exception or null