def METHOD_NAME(config, get_sheet_mocker):
    sheet = SmartSheetAPIWrapper(config)
    _ = get_sheet_mocker(sheet)
    json_schema = sheet.json_schema
    assert json_schema["$schema"] == "http://json-schema.org/draft-07/schema#"
    assert json_schema["type"] == "object"
    assert "properties" in json_schema
    assert "modifiedAt" in json_schema["properties"]