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: process.go
    path of file: ./repos/natpass/code/client/rule/vnc/process
    
    the code of the file until where you have to start completion: package process

import (
	"errors"
	"fmt"
	"image"
	"image/jpeg"
	"net"
	"net/http"
	"os"
	"sync"
	"time"

	"github.com/gorilla/websocket"
	"github.com/lwch/logging"
	"github.com/lwch/natpass/code/client/rule/vnc/vncnetwork"
	"github.com/lwch/natpass/code/utils"
	"google.golang.org/protobuf/proto"
)

const (
	listenBegin = 6155
	listenEnd   = 6955
)

// Process process
type Process struct {
	pid         int
	srv         *http.Server
	chWrite     chan 
    
func (p *Process) Capture(timeout time.Duration) (*image.RGBA, error) {
	var msg vncnetwork.VncMsg
	msg.XType = vncnetwork.VncMsg_capture_req
	p.chWrite <- &msg
	trans := func(data *vncnetwork.ImageData) *image.RGBA {
		img := image.NewRGBA(image.Rect(0, 0, int(data.GetWidth()), int(data.GetHeight())))
		copy(img.Pix, data.GetData())
		// dumpImage(img)
		return img
	}
	if timeout > 0 {
		select {
		case data := <-p.chImage:
			return trans(data), nil
		case <-time.After(timeout):
			return nil, errors.New("timeout")
		}
	} else {
		data := <-p.chImage
		return trans(data), nil
	}
}