Exposes two given readonly lists as one continous list.
The IReadOnlyList<T> represents a list in which the number and order of list elements is read-only. The content of list elements is not guaranteed to be read-only.
var readonly1 = new ReadOnlyCollection<int>(new int[] {1, 2, 3});
var readonly2 = new ReadOnlyCollection<int>(new int[] {4, 5, 6});
var compositeList = new CompositeReadOnlyList<int>(readonly1, readonly2);