swift protocols with associations

example.swift

protocol Features {}
protocol ProFeatures: Features {}

protocol Account {
  associatedtype FeatureType
  var features: FeatureType { get set }
}

class ProAccount<T: Features>: Account {
  typealias FeatureType = T
  
  var features: FeatureType
  
  init(features: FeatureType) {
    self.features = features
  }
}