DomainObjectSet

interface DomainObjectSet<T : Any> : MutableSet<T>

A set of domain objects of type T.

- The type of objects in this collection.

getAll	`abstract fun getAll(): MutableList<T>` Returns the elements of this set in the set's iteration order.
getAt	`abstract fun getAt(index: Int): T` Returns the element at the given index according to the set's iteration order.