object.and()

[hueniverse]

Creates an 'all or nothing' dependency between keys. Similar to object.with() with the difference that with() is between one context key and many others while and() is between all the listed keys:

with('a', ['b', 'c']) - if a is present, both b and c are required, but if a is not and b is, c is not required.
and('a', 'b', 'c') - if any of the listed keys is present, all of them are required.