如何跳过更新验证？

I have a custom validation on model, it allows me to check uniqueness of 1 field but related to another model, something like (1,2,3,4,5) -> User1, (1,2,3,4,5) -> User2, so because a value can actually exists for 2 different users but not 2 times for the same users I had to use a custom validator! Here is my code:I have a custom validation on model, it allows