disjoint union opt for exact object types
disjoint union opt for exact object types

Summary: Fixes incompleteness

Reviewed By: samwgoldman

Differential Revision: D7064431

fbshipit-source-id: c49a396d1fa8850745baf04244ecf93afc232380

JonathanUsername/flow,gabelevi/flow,JonathanUsername/flow,JonathanUsername/flow,jamesgpearce/flow,mroch/flow,claudiopro/flow,jamesgpearce/flow,JonathanUsername/flow,popham/flow,popham/flow,popham/flow,facebook/flow,facebook/flow,samwgoldman/flow,facebook/flow,mroch/flow,nmote/flow,nmote/flow,jamesgpearce/flow,gabelevi/flow,AgentME/flow,mroch/flow,samwgoldman/flow,mroch/flow,AgentME/flow,jamesgpearce/flow,JonathanUsername/flow,jamesgpearce/flow,mroch/flow,nmote/flow,samwgoldman/flow,gabelevi/flow,gabelevi/flow,JonathanUsername/flow,popham/flow,mroch/flow,facebook/flow,nmote/flow,AgentME/flow,claudiopro/flow,jamesgpearce/flow,jamesgpearce/flow,AgentME/flow,gabelevi/flow,samwgoldman/flow,nmote/flow,AgentME/flow,popham/flow,gabelevi/flow,samwgoldman/flow,mroch/flow,claudiopro/flow,JonathanUsername/flow,facebook/flow,facebook/flow,claudiopro/flow,popham/flow,claudiopro/flow,facebook/flow,samwgoldman/flow,samwgoldman/flow,nmote/flow,popham/flow,gabelevi/flow,nmote/flow