import unittest from common import gobject, testhelper TestInterface = gobject.type_from_name('TestInterface') class TestUnknown(unittest.TestCase): def testFoo(self): obj = testhelper.get_unknown() TestUnknownGType = gobject.type_from_name('TestUnknown') TestUnknown = gobject.new(TestUnknownGType).__class__ assert isinstance(obj, testhelper.Interface) assert isinstance(obj, TestUnknown)