go test -benchmem -bench=.
goos: linux
goarch: amd64
pkg: go.jolheiser.com/overlay
cpu: Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz
BenchmarkCache-8     	134959974	         9.003 ns/op	       0 B/op	       0 allocs/op
BenchmarkNoCache-8   	  897212	      1369 ns/op	     280 B/op	       4 allocs/op
PASS
ok  	go.jolheiser.com/overlay	3.360s