ImmutableDictionaryTKey, TValueItem Property

public TValue this[
	TKey key
] { get; set; }

Public Default Property Item ( 
	key As TKey
) As TValue
	Get
	Set

public:
virtual property TValue default[TKey key] {
	TValue get (TKey key) sealed;
	void set (TKey key, TValue value) sealed;
}

abstract Item : 'TValue with get, set
override Item : 'TValue with get, set

function get_Item(key);
function set_Item(value);