public void RemoveAllTest1()
{
var bag = new SortedBag <int> {
3, 5, 1, 1, 4, 6, 2, 2, 2
};
Assert.Equal(9, bag.Count);
Assert.Equal(2, bag.RemoveAll(1));
Assert.Equal(7, bag.Count);
Assert.Equal(0, bag.RemoveAll(10));
Assert.Equal(7, bag.Count);
Assert.Equal(3, bag.RemoveAll(2));
Assert.Equal(4, bag.Count);
Assert.Equal(1, bag.RemoveAll(5));
Assert.Equal(3, bag.Count);
}