def _oldGiInit():
    """
    Make sure pygtk and gi aren't loaded at the same time, and import Glib if
    possible.
    """
    # We can't immediately prevent imports, because that confuses some buggy
    # code in gi:
    _glibbase.ensureNotImported(
        _PYGTK_MODULES,
        "Introspected and static glib/gtk bindings must not be mixed; can't "
        "import gireactor since pygtk2 module is already imported.")

    global GLib
    from gi.repository import GLib
    if getattr(GLib, "threads_init", None) is not None:
        GLib.threads_init()

    _glibbase.ensureNotImported([], "",
                                preventImports=_PYGTK_MODULES)

    Make sure pygtk and gi aren't loaded at the same time, and import Glib if
    possible.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/gireactor.py