public void Delete_HeadTest()
{
//删除前1 2 3 4 5
node1.Delete();
//删除后 2 3 4 5
Assert.IsNull(node1.Next);
Assert.IsNull(node2.Previous);
//删除前 2 3 4 5
node2.Delete();
//删除后 3 4 5
Assert.IsNull(node2.Next);
Assert.IsNull(node3.Previous);
//删除前 3 4 5
node3.Delete();
//删除后 4 5
Assert.IsNull(node3.Next);
Assert.IsNull(node4.Previous);
//删除前 4 5
node4.Delete();
//删除后 5
Assert.IsNull(node4.Next);
Assert.IsNull(node5.Previous);
//最后一个无法被删除
node5.Delete();
Assert.IsNull(node5.Previous);
Assert.IsNull(node5.Next);
}
