def METHOD_NAME(syn):
    """Test that "folder" is added to include types"""
    with patch.object(
        synapseutils.walk_functions, "_helpWalk", return_value="test"
    ) as mock_helpwalk:
        results = synapseutils.walk(syn=syn, synId="syn123", includeTypes=["file"])
        # Execute generator
        mock_helpwalk.assert_called_once_with(syn, "syn123", ["file", "folder"])
        # Make sure correct value is returned
        assert results == "test"