code: private boolean isCenter(Tile tile)
      {
          for (final Transition transition : tiles.get(new TileRef(tile)))
          {
              if (TransitionType.CENTER == transition.getType())
              {
                  return true;
              }
          }
          return false;
      }
docs: Check if tile is a center.
  
  @param tile The tile to check.
  @return <code>true</code> if center, <code>false</code> else.