internal BlockCommands( World _world, Commands commands ) {
world = _world;
commands.AddCommand( "grass", Grass, false );
commands.AddCommand( "water", Water, false );
commands.AddCommand( "lava", Lava, false );
commands.AddCommand( "solid", Solid, false );
commands.AddCommand( "s", Solid, false );
commands.AddCommand( "paint", Paint, false );
//CommandUtils.AddCommand( "sand", Sand ); // TODO: after sand sim is done
}