How many prediction classes with "has" captions are there for image id 3050?
prediction classes with "has" captions refers to PRED_CLASS = 'has'; image id 3050 refers to IMG_ID = 3050
SELECT COUNT(T2.PRED_CLASS_ID) FROM IMG_REL AS T1 INNER JOIN PRED_CLASSES AS T2 ON T1.PRED_CLASS_ID = T2.PRED_CLASS_ID WHERE T1.IMG_ID = 3050 AND T2.PRED_CLASS = 'has'