minor refactor for @fixme_fat_interface
minor refactor for @fixme_fat_interface

Reviewed By: tyao1

Differential Revision: D24873104

fbshipit-source-id: 6755dc304691bd7004a8bf98d5a67b1d09968fa0

facebook/relay,josephsavona/relay,voideanvalue/relay,josephsavona/relay,voideanvalue/relay,kassens/relay,facebook/relay,xuorig/relay,yungsters/relay,xuorig/relay,xuorig/relay,josephsavona/relay,wincent/relay,wincent/relay,kassens/relay,facebook/relay,voideanvalue/relay,atxwebs/relay,voideanvalue/relay,yungsters/relay,kassens/relay,kassens/relay,wincent/relay,yungsters/relay,atxwebs/relay,wincent/relay,voideanvalue/relay,xuorig/relay,wincent/relay,kassens/relay,xuorig/relay,kassens/relay,wincent/relay,facebook/relay,facebook/relay,facebook/relay,xuorig/relay,atxwebs/relay,atxwebs/relay,voideanvalue/relay