ConstructorsVisibility.kt

// User is public
// The User primary constructor is private
class User private constructor(id : Int) {
  // ...
}

// Moderator is internal
// The Moderator primary constructor is private
internal Moderator private constructor(id : Int) {
  // ...
}

// Staff is internal
// The Staff primary constructor is public, but it's
// visibility is restricted by the class internal modifier
internal Staff(id : Int) {
  // ...
}