code: public final StringProperty locationProperty() {
          if (location == null) {
              location = new SimpleStringProperty(null, "location") { //$NON-NLS-1$
                  @Override
                  public void set(String newLocation) {
                      String oldLocation = get();
  
                      if (!Util.equals(oldLocation, newLocation)) {
  
                          super.set(newLocation);
  
                          Calendar calendar = getCalendar();
                          if (calendar != null) {
                              calendar.fireEvent(new CalendarEvent(CalendarEvent.ENTRY_LOCATION_CHANGED, calendar, Entry.this, oldLocation));
                          }
                      }
                  }
              };
          }
  
          return location;
      }
docs: A property used to store a free-text location specification for the given
  entry. This could be as simple as "New York" or a full address as in
  "128 Madison Avenue, New York, USA".
  
  @return the location of the event specified by the entry