public void TestRemoveRange()
{
ImmutableTreeDictionary <int, int> .Builder dictionary = ImmutableTreeDictionary.CreateBuilder <int, int>();
for (int i = 0; i < 10; i++)
{
dictionary.Add(i, i);
}
int[] itemsToRemove = dictionary.Keys.Where(i => (i & 1) == 0).ToArray();
dictionary.RemoveRange(itemsToRemove);
Assert.Equal(new[] { 1, 3, 5, 7, 9 }.Select(x => new KeyValuePair <int, int>(x, x)), dictionary);
Assert.Throws <ArgumentNullException>("keys", () => dictionary.RemoveRange(null !));
}
