Allowing nil substitution values in production.
Release 1.6.4.
Whitespace.
Possible edge cases.
Release 1.6.5.
Return object identifiers
Send object ids across threads
Need object method as well
Fix args
Background context
Use forked stack as direct dependency
Thread-safe date formatters
Workaround? Remove object from cache when deleted from context
Revert "Workaround? Remove object from cache when deleted from context"

This reverts commit a1e06fa94467bba8e4ba931045f7d01986303760.
Use existingObjectWithID:error:?