As far as I can tell (primarily from reading docs), there's no obvious capability for checking instanceof on a Joi ValidationError.

This makes writing assertions with Code difficult, e.g. I'd like to able to do something like:

const Joi = require('joi')
const expect = require('code').expect

function throws() {
    Joi.assert('x', Joi.number())
}

expect(throws).to.throw(Joi.ValidationError)

Am I missing something? If not, thoughts on adding this capability?