A new SkipList<int> contains 0

[Hoodedgull]

Describe the bug
A new SkipList<int> contains 0 (zero). It should not contain any numbers before any numbers are added.

To Reproduce
Steps to reproduce the behavior:

1. Create a new SkipList of integers
   var list = new SkipList<int>();
2. Check if it contains 0:
   var result = list.Contains(0)
3. Result is true.

Expected behavior
I would expect (new SkipList<int>()).Contains(0) to return false.

Environmnet:

• OS: Windows
• .NET Version: .NET Core v3.1.101
• IDE: Visual Studio Enterprise 2019