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 literal_eval(node_or_string):
    if isinstance(node_or_string, AST):
        node_or_string = gast_to_ast(node_or_string)
    return _ast.literal_eval(node_or_string)