code: void removeTileData(Tile from, Tile to) {
          if (overlapData.containsKey(from)) {
              overlapData.get(from).remove(to);
          }
  
      }
docs: Cache maintenance operation to remove data for a tile from the cache. This should be excuted
  if a tile is removed from the TileCache and will be drawn again.
  
  @param from