// PREDICT: what happens? Can recover() save you? Run it a few times.
// Then run with: go run -race .
package main

import (
	"fmt"
	"time"
)

func main() {
	defer func() {
		if r := recover(); r != nil {
			fmt.Println("recovered:", r) // will this ever print?
		}
	}()
	m := make(map[int]int)
	for i := 0; i < 100; i++ {
		go func(i int) { m[i] = i }(i)
	}
	time.Sleep(200 * time.Millisecond)
	fmt.Println(len(m))
}