docs: public static String getVersion() {
          if (version == null) {
  
              InputStream stream = CalendarFX.class.getResourceAsStream("version.properties"); //$NON-NLS-1$
              Properties props = new Properties();
              try {
                  props.load(stream);
              } catch (IOException ex) {
                  LoggingDomain.CONFIG.throwing(CalendarFX.class.getName(), "getVersion()", ex); //$NON-NLS-1$
              }
  
              version = props.getProperty("calendarfx.version", "1.0.0"); //$NON-NLS-1$ //$NON-NLS-2$
  
              LoggingDomain.CONFIG.info("CalendarFX Version: " + version); //$NON-NLS-1$
          }
          return version;
      }