code: private void addTileCollisions(MapTileCollision mapCollision, TileCollision tileCollision, Tile tile)
      {
          final TileRef ref = new TileRef(tile);
          for (final CollisionGroup collision : mapCollision.getCollisionGroups())
          {
              final Collection<TileRef> group = mapGroup.getGroup(collision.getName());
              if (group.contains(ref))
              {
                  for (final CollisionFormula formula : collision.getFormulas())
                  {
                      tileCollision.addCollisionFormula(formula);
                  }
              }
          }
      }
docs: Add the tile collisions from loaded configuration.
  
  @param mapCollision The map tile collision owner.
  @param tileCollision The tile reference.
  @param tile The tile reference.