You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: expiring_message.go
    path of file: ./repos/dry/ui
    
    the code of the file until where you have to start completion: package ui

import (
	"sync"
	"time"
)

// ExpiringMessageWidget shows some text for an amount time then clears itself
type ExpiringMessageWidget struct {
	y           int
	screenWidth int
	clearTimer  *time.Timer
	screen      *Screen

	sync.RWMutex
	message string
}
    
func (s *ExpiringMessageWidget) Message(msg string, clearDelay time.Duration) {
	s.Lock()
	defer s.Unlock()
	s.stopTimer()
	s.message = msg
	if clearDelay == 0 {
		return
	}
	s.clearTimer = time.AfterFunc(clearDelay, func() {
		s.Lock()
		s.message = ""
		s.Unlock()
		ActiveScreen.Fill(0, s.y, len(msg), 1, ' ')
	})

}