package main
import "net/http"
import "time"

func example() {
	// Programmer here mistakenly defined a constant as 5, instead of 5 * time.Seconds
	const timeout = 5
	
	// When using a literal, or an untyped constant like the one above, in a 
	// place where a time.Duration is expected, the value gets automatically
	// promoted, resulting in a 5 nanosecond timeout being used.
	// All the following uses are flagged by the check:
	_ = http.Client { Timeout: timeout }
	var duration time.Duration = timeout
	time.Sleep(timeout)
	time.Sleep(5)
	
	// Values typed to time.Duration are allowed, so you can explicitly cast to
	// time.Duration to silence the check.
	// The following uses are not flagged:
	time.Sleep(time.Duration(5))
	time.Sleep(5 * time.Second)
	const correctTimeout = 5  * time.Second
	time.Sleep(correctTimeout)
}