Can a subdocument be required in mongoose?

Is it possible to have nested schemas in mongoose and have a required validator on the children? Something like this:

const userSchema = new mongoose.Schema({
  name: {
    type: String,
    required: true
  }
});

const eventSchema = new mongoose.Schema({
  name: {
    type: String,
    required: true
  },
  host: {
    type: userSchema,
    required: true
  }
});

I can't find anything in the documentation. Thanks.

via Elias Garcia