TypeSpec #2467

I was exploring Python.NET API, and while looking PyType class, I found a constructor that accepts a TypeSpec.
So, I got curious and peeked the definition of TypeSpec, and I found the constructor. I can fill every argument of the constructor, except the basicSize parameter.
I'm not so used to dealing with the C API of Python directly, so I searxhed and apparently the basic size is the PyObject_HEAD size + fields that the type supports it.
So I tried to find references to TypeSpec in Python.NET code andthe only references I found are in the NativeTypeSpec constructor, inside TypeManager code and inside a test.
All of these references I linked here are internal parts of Python.NET and/or uses internal functionality (example: reading type offsets and marshalling from string to StrPtr).
Now my question is: Is TypeSpec actually meant to be consumed externally by developers?