Here are the first lines of the file sleep.go
in the time
package of the Go core library:
// Sleep pauses the current goroutine for at least the duration d.
// A negative or zero duration causes Sleep to return immediately.
func Sleep(d Duration)
// runtimeNano returns the current value of the runtime clock in nanoseconds.
func runtimeNano() int64
Why is there no declaration of the function time.Sleep
here? Where is it?