code: public static void init(File file) {
          if (null != engine) throw new IllegalStateException("Rythm is already initialized");
          engine = new RythmEngine(file);
          engine.setShutdownListener(new RythmEngine.IShutdownListener() {
              @Override
              public void onShutdown() {
                  _Rythm.engine = null;
              }
          });
      }
docs: Initialize default engine instance with specified configuration file
  <p/>
  <p>Note this method can not be called more than once during a JVM lifecycle.
  if the default engine instance is created already then
  an <code>IllegalStateException</code> will be thrown out</p>
  <p/>
  <p>When the default engine's {@link org.rythmengine.RythmEngine#shutdown() shutdown} method get called
  the default engine instance will be discard. Calling any servicing method of
  <code>Rythm</code> will cause an new <code>RythmEngine</code> initialized as
  the new default engine</p>
  
  @param file the configuration file