code: public boolean tick (Pathable pable, long tickstamp)
      {
          if (tickstamp >= _startStamp + _duration) {
              if (_source != null) {
                  pable.setLocation(_source.x, _source.y);
              }
              pable.pathCompleted(tickstamp);
              return (_source != null);
          }
  
          // If necessary, move the sprite to the supplied location
          if (_source != null && (pable.getX() != _source.x ||
                                  pable.getY() != _source.y)) {
              pable.setLocation(_source.x, _source.y);
              return true;
          }
  
          return false;
      }
docs: documentation inherited