add sample test (#439)
add sample test (#439)

* add sample test

* review comments

parthea/pydatalab,yebrahim/pydatalab,parthea/pydatalab,yebrahim/pydatalab,yebrahim/pydatalab,googledatalab/pydatalab,googledatalab/pydatalab,parthea/pydatalab,craigcitro/pydatalab,supriyagarg/pydatalab,craigcitro/pydatalab,googledatalab/pydatalab,supriyagarg/pydatalab,craigcitro/pydatalab,supriyagarg/pydatalab