var userSchema = new Schema({
      name: { type: String, required: true },
      roles: { type: [userRoleSchema]: default [] }
})

var userRoleSchema = new Schema({
      type: { type: String, required: true },
      organization: { type: Schema.Types.ObjectId, ref: 'organization', required: false },
})

// Later when I call this
userDocument.validate((err) => { /* I don't even end up here */ })