unit test for ResizableArray.to_hashtbl
unit test for ResizableArray.to_hashtbl

Reviewed By: nmote

Differential Revision: D16472773

fbshipit-source-id: c00af8c81deaf099d4cfe3d9f9a07a750a1fb35e

nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow