It's used only as a dev dependency in 6 crates.

Depender (with downloads and own rev deps) riker-testkit version
140 11 riker dev ^0.1.0
1 riker-timer dev ^0.1.0
1 riker-mapvec dev ^0.1.0
riker-cqrs dev ^0.1.0
2 riker-patterns dev ^0.1.0
actors-rs dev ^0.1.0