If namespace namespace_ is loaded, return the full path to the .
typelib file it was loaded from. If the typelib for namespace namespace_ was included in a shared library, return the
special string "<builtin>".
| this |
A Repository or null for the singleton process-global default Repository |
| namespace_ |
GI namespace to use, e.g. "Gtk" |
|
Filesystem path (or $lt;builtin$gt;) if successful, null if namespace is not loaded |