func WithPrefix(prefix string) BuildTarOption {
	return func(o *BuildTarOptions) {
		o.Prefix = prefix
	}
}
WithPrefix is an option to add a prefix string to each file name (e.g. "./", "/", etc.)
package testutil
import (
	"archive/tar"
	"fmt"
	"io"
	"os"
	"strings"
	"time"
)
type TarEntry interface {
	AppendTar(tw *tar.Writer, opts BuildTarOptions) error
}
type BuildTarOptions struct {
	Prefix string
}
type BuildTarOption func(o *BuildTarOptions)