unit tests
unit tests

Summary: added unit tests

Reviewed By: junzh0u

Differential Revision: D18864452

fbshipit-source-id: bd0fe324e132a6409078bf73e6556ad780aaf495

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift