public void ClearsSource()
{
var dictionary = new Dictionary <int, string>()
{
{ 1, "one" },
{ 2, "two" },
{ 3, "three" }
};
var forwarderDictionary = new DictionaryAdapter <int, string>(
dictionary.TryGetValue,
() => dictionary.Keys,
(key, value) => dictionary[key] = value,
dictionary.Remove);
forwarderDictionary.Clear();
Assert.Empty(dictionary);
}