$ go test -bench=. -benchmem .
goos: darwin
goarch: amd64
pkg: github.com/squaresun/getter-benchmark
BenchmarkServeInterface-8 3000000 410 ns/op
BenchmarkServeStruct-8 20000000 76.5 ns/op
PASS
ok github.com/squaresun/getter-benchmark 3.270s