validation rule

基本解释

Supports a model validation rule that warns you when semantic elements are placed in Package
支持一个模型验证规则，它警告您语义学元素何时被放置到包中。
Rather than having each object maintain its own validation, you merely encode the correct validation rule for each object.
您只要为每个对象编码正确的验证规则，而不是让每个对象维护自己的验证。
This isn't ideal because it forces users to do more work and forces you to write another validation rule to make sure that they did it correctly.
这种做法不是很理想，因为它要求用户做更多的工作，而且还要求必须要编写另一个验证规则来确保用户能正确输入。