如何使用变量引用类常量

I have a class:

我上课了：

class VoteType < MyModel
    UPVOTE          = where(slug: "up-vote").pluck(:id).first
    DOWNVOTE        = where(slug: "down-vote").pluck(:id).first
    FAVORITE        = where(slug: "favorite").pluck(:id).first
    SPAM                = where(slug: "spam").pluck(:id).first
end
class VoteType < MyMo