This library is for marking periods of time and events in those periods.
```rust use performance_mark::Performance; use std::thread::sleep; use std::time::Duration;
fn main() { let wait = Duration::from_millis(100);
let mut perf = Performance::new();
perf.mark("start");
sleep(wait);
perf.start("middle"); sleep(wait); perf.end("middle");
sleep(wait);
perf.mark("end");
println!("{:?}", perf.events());
asserteq!(perf.events().len(), 2); assert!(perf.events()[0] < perf.events()[1]); asserteq!(perf.periods().len(), 1); assert!(perf.periods().get("middle").unwrap().duration() >= wait); } ```