Compilation warning
In file included from /Users/Binbin/Documents/A trier/Solarus/engine/src/entities/CustomEntity.cpp:17:
/Users/Binbin/Documents/A trier/Solarus/engine/include/solarus/entities/CustomEntity.h:200:21: warning: private field 'lua_context' is not used [-Wunused-private-field]
LuaContext* lua_context; /**< The Lua world.