'Returns ``GuardedModelAdmin`` instance.'

def _get_gma(self, attrs=None, name=None, model=None):

    attrs = (attrs or {})
    name = str((name or u'GMA'))
    model = (model or User)
    GMA = type(name, (GuardedModelAdmin,), attrs)
    gma = GMA(model, admin.site)
    return gma
