public void GetIndexCharTest()
{
List <string> chars1 = new List <string>();
List <string> chars2 = new List <string>();
for (int i = 0; i < 12; i++)
{
chars1.Add(VirtualRoot.GetIndexChar(i, string.Empty));
chars2.Add(VirtualRoot.GetIndexChar(i, ","));
}
Assert.AreEqual("0123456789ab", string.Join(string.Empty, chars1));
Assert.AreEqual("0,1,2,3,4,5,6,7,8,9,10,11", string.Join(",", chars2));
}