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/bud/internal/testcli
    
    the code of the file until where you have to start completion: package testcli

import (
	"bytes"
	"context"
	"io"
	"net/http"
	"os"
	"path/filepath"

	"github.com/livebud/bud/internal/extrafile"

	"github.com/livebud/bud/internal/once"
	"github.com/livebud/bud/internal/shell"
)

// StartApp starts bud/app. It's meant to be used after running `bud build`.
// TODO: integrate better with testcli
func (c *CLI) StartApp(ctx context.Context, args ...string) (*Process, error) {
	webLn, webc, err := listen(":0")
	if err != nil {
		return nil, err
	}
	stdout := new(bytes.Bu
    
func (c *CLI) StartApp(ctx context.Context, args ...string) (*Process, error) {
	webLn, webc, err := listen(":0")
	if err != nil {
		return nil, err
	}
	stdout := new(bytes.Buffer)
	stderr := new(bytes.Buffer)
	cmd := shell.Command{
		Dir:    c.dir,
		Env:    c.Env.List(),
		Stdin:  c.Stdin,
		Stdout: io.MultiWriter(os.Stdout, stdout),
		Stderr: io.MultiWriter(os.Stderr, stderr),
	}
	closer := new(once.Closer)
	webFile, err := webLn.File()
	if err != nil {
		return nil, err
	}
	closer.Add(webFile.Close)
	extrafile.Inject(&cmd.ExtraFiles, &cmd.Env, "WEB", webFile)
	args = append(args, "--listen", webLn.Addr().String())
	process, err := cmd.Start(ctx, filepath.Join("bud", "app"), prependFlags(args)...)
	if err != nil {
		return nil, err
	}
	closer.Add(process.Close)
	return &Process{
		closer: closer,
		stdout: stdout,
		stderr: stderr,
		webc:   webc,
	}, nil
}