func WriteProxy(tmpdir string, files map[string][]byte) (string, error) {
	type moduleVersion struct {
		modulePath, version string
	}
	filesByModule := make(map[moduleVersion]map[string][]byte)
	for name, data := range files {
		modulePath, version, suffix := splitModuleVersionPath(name)
		mv := moduleVersion{modulePath, version}
		if _, ok := filesByModule[mv]; !ok {
			filesByModule[mv] = make(map[string][]byte)
		}
		filesByModule[mv][suffix] = data
	}
	for mv, files := range filesByModule {
		if err := proxydir.WriteModuleVersion(tmpdir, mv.modulePath, mv.version, files); err != nil {
			return "", fmt.Errorf("error writing %s@%s: %v", mv.modulePath, mv.version, err)
		}
	}
	return proxydir.ToURL(tmpdir), nil
}
WriteProxy creates a new proxy file tree using the txtar-encoded content,
and returns its URL.
package fake
import (
	"fmt"
	"github.com/govim/govim/cmd/govim/internal/golang_org_x_tools/proxydir"
)