The internals namespace hierarcy consists of a number of namespaces collecting calls for gaining low-level access to internal MakeHuman functionality.
In the vast majority of cases, you would benefit from first trying to find a relevant call elsewhere in the API, and as a last resort look here.
Get the central human object.
Get the central app object.
Get the human's skeleton, if any.
Get the python array type code that is closest to the given numpy type code.