$ cargo test
Compiling cacher v0.1.0 (file:///projects/cacher)
Finished test [unoptimized + debuginfo] target(s) in 0.72s
- Running target/debug/deps/cacher-4116485fb32b3fff
+ Running unittests (target/debug/deps/cacher-074d7c200c000afa)
running 1 test
test tests::call_with_different_values ... FAILED