code: public void loadCollisions(MapTileCollision mapCollision, Media collisionFormulas, Media collisionGroups)
      {
          if (collisionFormulas.exists())
          {
              loadCollisionFormulas(collisionFormulas);
          }
          if (collisionGroups.exists())
          {
              loadCollisionGroups(mapCollision, collisionGroups);
          }
          loadTilesCollisions(mapCollision);
          applyConstraints();
      }
docs: Load map collision from an external file.
  
  @param mapCollision The map tile collision owner.
  @param collisionFormulas The collision formulas descriptor.
  @param collisionGroups The tile collision groups descriptor.
  @throws LionEngineException If error when reading collisions.