Question: How many samples of "wall" are there in image no.2353079?
SQL: SELECT SUM(CASE WHEN T1.OBJ_CLASS = 'wall' THEN 1 ELSE 0 END) FROM OBJ_CLASSES AS T1 INNER JOIN IMG_OBJ AS T2 ON T1.OBJ_CLASS_ID = T2.OBJ_CLASS_ID WHERE T2.IMG_ID = 2353079