The ImmutableLinkedHashMap<K, V> class implements the
IImmutableDictionary<K, V> interface. It has ImmutableDictionary<K, V> and
ImmutableArray<T> (where T stands for KeyValuePair<K, V>) to maintain the
elements so that it has predictable iteration order, like that of the
LinkedHashMap class in Java.
The ImmutableArray<T> keeps the iteration order corresponding to the
insertion order in which you insert key-value pairs into the map. Note that
the insertion order is not affected when you re-inserted any key into it (i.e.,
with the SetItem(K, V) method).