The California Shakespeare Theater's four-play season always includes at least one non-Shakespeare work, and in both last season and this one that work has been by the great George Bernard Shaw. Last year's production of Mrs. Warren's Profession proved to us that Shaw could still feel vitally relevant, and even fresh, in the modern day. The current production of Candida, while still a fine example of Shaw's wit and emotional subtlety, feels less vital and somewhat more dated — if only because it centers around an Anglican clergyman and his wife who are active in the age of Christian socialism in England. But it's nonetheless an amusing examination of a marriage.