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: common_coverage.go
    path of file: ./repos/v2ray-core/testing/scenarios
    
    the code of the file until where you have to start completion: // +build coverage

package scenarios

import (
	"bytes"
	"os"
	"os/exec"

	"v2ray.com/core/common/uuid"
)

func BuildV2Ray() error {
	genTestBinaryPath()
	if _, err := os.Stat(testBinaryPath); err == nil {
		return nil
	}

	cmd := exec.Command("go", "test", "-tags", "coverage coveragemain", "-coverpkg", "v2ray.com/core/...", "-c", "-o", testBinaryPath, GetSourcePat
    
func RunV2RayProtobuf(config []byte) *exec.Cmd {
	genTestBinaryPath()

	covDir := os.Getenv("V2RAY_COV")
	os.MkdirAll(covDir, os.ModeDir)
	randomID := uuid.New()
	profile := randomID.String() + ".out"
	proc := exec.Command(testBinaryPath, "-config=stdin:", "-format=pb", "-test.run", "TestRunMainForCoverage", "-test.coverprofile", profile, "-test.outputdir", covDir)
	proc.Stdin = bytes.NewBuffer(config)
	proc.Stderr = os.Stderr
	proc.Stdout = os.Stdout

	return proc
}