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: main.go
    path of file: ./repos/bubbletea/examples/debounce
    
    the code of the file until where you have to start completion: package main

// This example illustrates how to debounce commands.
//
// When the user presses a key we increment the "tag" value on the model and,
// after a short delay, we include that tag value in the message produced
// by the Tick command.
//
// In a subsequent Update, if the tag in the Msg matches current tag on the
// model's state we know that the debouncing is complete and we can proceed as
// normal. If not, we simply ignore the inbound message.

import (
	"fmt"
	"os"
	"time"

	tea "github.com/charmbracelet/bubbletea"
)

const debounceDuration = time.Second

type exitMsg int

type model struct {
	tag int
}

func (m model) Init() tea.Cmd {
	retu
    
func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		// Increment the tag on the model...
		m.tag++
		return m, tea.Tick(debounceDuration, func(_ time.Time) tea.Msg {
			// ...and include a copy of that tag value in the message.
			return exitMsg(m.tag)
		})
	case exitMsg:
		// If the tag in the message doesn't match the tag on the model then we
		// know that this message was not the last one sent and another is on
		// the way. If that's the case we know, we can ignore this message.
		// Otherwise, the debounce timeout has passed and this message is a
		// valid debounced one.
		if int(msg) == m.tag {
			return m, tea.Quit
		}
	}

	return m, nil
}