Comparer<T> code snippet issues

https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.comparer-1?view=net-8.0#examples

In the examples code snippet, the comment above the declaration of `LengthFirst` talks about an explicit interface implementation, but I don't see this anywhere in the snippet.

The snippet has some other issues too, including:
1. Local variables named in pascal case (`Boxes`, `LengthFirst`, `BoxA` and `BoxB`)
2. Ancient string formatting (should be using string interpolation instead)
3. Unused variables (`defComp`, `bc`)
4. Weird variable names (why `bx` instead of `box`, why `defComp` instead of `defaultComparer`, what is `bc`?)
5. The `Compare` methods could use some variables for clarity and code quality
6. Use collection expression for creating the list