Django：如何针对另一个相关表单验证inlineformset

I have looked around quite a bit but can't quite figure out how to make this work. I basically have a Document form and an Item inlineformset in a view, and I need to perform some validation dependent on the field values in each form. For example, if the Item's copyright_needed field is YES then the Document's account field is required. I have looked around quite a bit but can't quit