public void RemoveTest()
{
var gb = new GapBuffer <int>(4);
gb.InsertRange(0, new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 }, 0, 9);
gb.RemoveRange(3, 4);
Assert.Equal(5, gb.Count);
Assert.Equal(1, gb[0]);
Assert.Equal(2, gb[1]);
Assert.Equal(3, gb[2]);
Assert.Equal(8, gb[3]);
Assert.Equal(9, gb[4]);
}