What is the average processed time of the solution with a repository of 254 likes, 88 followers, and 254 watchers?
average processed time = AVG(ProcessedTime);
SELECT CAST(SUM(T2.ProcessedTime) AS REAL) / COUNT(T2.ProcessedTime) FROM Repo AS T1 INNER JOIN Solution AS T2 ON T1.Id = T2.RepoId WHERE T1.Stars = 254 AND T1.Forks = 88 AND T1.Watchers = 254