code: package org.omnetpp.eventlog;
  
  /**
   * Variables which store event numbers throughout the API may have these
   * additional values (positive values are real event numbers).
   */
  public class EventNumberKind
  {
      /**
       * The event number is not yet calculated before.
       */
      public static int EVENT_NOT_YET_CALCULATED = -1;
  
      /**
       * There is no such event and will never be because it is impossible. (e.g. the previous event of the first event)
       */
      public static int NO_SUCH_EVENT = -2;
  
      /**
       * The event is not and will never be in the log, although it could be. (e.g. filtered by the user from the file)
       */
      public static int FILTERED_EVENT = -3;
  
      /**
       * The event is not yet in the log, but it might appear in the future (e.g. simulation not there yet).
       * The last event number is added to the constant and returned.
       * (e.g. reading the event 1000 when the file ends at 100 will give -104)
       */
      public static int EVENT_NOT_YET_REACHED = -4;
  }
  