def wasSolvedBy(self, user):
thisExercise = _Solution.what == self<EOL>byThisUser = _Solution.who == user<EOL>condition = q.AND(thisExercise, byThisUser)<EOL>return self.store.query(_Solution, condition, limit=<NUM_LIT:1>).count() == <NUM_LIT:1><EOL>
Checks if this exercise has previously been solved by the user.