public static OMMapManager getInstance() {
    if (instanceRef.get() == null) {
      synchronized (instanceRef) {
        if (instanceRef.compareAndSet(null, createInstance())) {
          instanceRef.get().init();
        }
      }
    }
    return instanceRef.get();
  }
public static OMMapManager getInstance ( ) { if ( instanceRef . get ( ) == null ) { synchronized ( instanceRef ) { if ( instanceRef . compareAndSet ( null , createInstance ( ) ) ) { instanceRef . get ( ) . init ( ) ; } } } return instanceRef . get ( ) ; }
This method returns instance of mmap manager.

@return mmap manager instance. If it is not exist create new one.