Can you add any example for option "dependsOn"

I have a model below

var User = new keystone.List('User')
User.add({
    email: { type: Types.Email, initial: true, required: true, index: true },
    country: { type: Types.Select, options: ['usa', 'thailand', 'vietnam'], emptyOption: false},
    city: { depends on country field but how to fill here?!!! }
})

I see you supported the dependsOn option in document page

dependsOn Object    The field will only be displayed when the paths specified in the object match the current data for the item

But don’t see any example for this? Can you help me? Thanks 😃

[sokki]

+1 for the ability to pass a function to dependsOn (and maybe other things like options)

In my case, I need to hide a field depending on a fieldvalue of a document that is linked by a relation …

[mxstbr]

Moved to keystonejs-site: https://github.com/keystonejs/keystonejs-site/issues/87