add test case for not accepting write/append modes
add test case for not accepting write/append modes

EntilZha/PyFunctional,EntilZha/PyFunctional,lucidfrontier45/ScalaFunctional,EntilZha/ScalaFunctional,EntilZha/ScalaFunctional,ChuyuHsu/ScalaFunctional,lucidfrontier45/ScalaFunctional,ChuyuHsu/ScalaFunctional