Path.GetFullPath() refers to methods that do not exist in Framework

https://docs.microsoft.com/dotnet/api/system.io.path.getfullpath?view=netframework-4.8 states:

> To return a deterministic path, call the GetFullPath(String, String) overload. You can also call the IsPathFullyQualified method to determine whether a path is fully qualified or relative and therefore whether a call to GetFullPath is necessary.

with a link to the aforementioned overload. However, `Path.GetFullPath(String, String)` doesn't exist in any version of the Framework.

`Path.IsPathFullyQualified(String)` also does not exist in the Framework.