final Map<Artifact, File> fromTo = compute(artifacts, resourceTargetFile(moduleDirectory));
final Map<File, Future<String>> targetHashes = sha1async(fromTo.values());
final Pool pool = Resources.getPoolHandle();
final ExecutorService executor = pool.aquireExec();
try {
return collect(ImmutableList.copyOf(transform(fromTo.entrySet(),
new Function<Entry<Artifact, File>, Future<String>>() {
@Override
public Future<String> apply(final Entry<Artifact, File> e) {