Have a validation case that I'm not sure how to cover.
My existing check is this...

Joi.object().keys({
    businessDivision: Joi.number().integer().positive(),
    masterProgram: Joi.number().integer().positive(),
    profile: Joi.number().integer().positive()
}).xor('businessDivision', 'masterProgram')

Which is fine for ensuring that not both businessDivision and masterProgram are present. But it also has the side effect of requiring at least 1 of them be present.
For my use case both being absent would be just fine.

I can't use .limit(1) because of the unrelated profile key which is optional.

I know I could use .without(...) for a simple case (like above) of just 2 that need to be exclusive but that doesn't expand well to a case where maybe more keys need to be exclusive or but not any required.

Is there a simple way to do this, that also expands to the larger possible key sets as well?