def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def is_user_addon(mod, user_addon_paths):
        import os

        if not user_addon_paths:
            for path in (bpy.utils.script_path_user(),
                         bpy.utils.script_path_pref()):
                if path is not None:
                    user_addon_paths.append(os.path.join(path, "addons"))

        for path in user_addon_paths:
            if bpy.path.is_subdir(mod.__file__, path):
                return True
        return False