//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test void addRemoveAll()
internal virtual void AddRemoveAll()
{
_set.addAll(1, 2, 3, 1, 2, 3, 100, 200, 300);
assertEquals(6, _set.size());
assertTrue(_set.containsAll(100, 200, 300, 1, 2, 3));
_set.removeAll(1, 2, 100, 200);
assertEquals(2, _set.size());
assertTrue(_set.containsAll(300, 3));
_set.removeAll(3, 300);
assertEquals(0, _set.size());
}