Summary: This helps Kotlin nullity inference and *should* already be enforced by Infer/Eradicate. More details here: https://medium.com/square-corner-blog/non-null-is-the-default-58ffc0bb9111 Reviewed By: jknoxville Differential Revision: D13732788 fbshipit-source-id: c0c60f0f8e9dc8bffe3780c7a1a700d682a6d2b8