code: public boolean addEvent(GridEvent e)
    {
      BitSet eventOccupance = new BitSet(e.getRight());
      eventOccupance.set(e.getLeft(), e.getRight()+1, true);
      if(occupancySet.intersects(eventOccupance))
      {
        return false;
      }
      // set all bits to true that are covered by the other event
      occupancySet.or(eventOccupance);
      events.add(e);
  
      if(e.getTextID() != null && !e.getTextID().isEmpty())
      {
        textIDs.add(e.getTextID());
      }
  
      return true;
    }
docs: Adds an event to this row
  @param e
  @return False if could not be added because the event is overlapping an
  other event in the row.