}
long lastModified = packageJson.lastModified();
String path = packageDir.getAbsolutePath();
TimestampedSemVer r = PACKAGE_VERSION_CACHE.get(path);
if (r == null || r.getTimestamp() != lastModified) {
SemVer semver = calc(packageJson);
r = new TimestampedSemVer(lastModified, semver);
PACKAGE_VERSION_CACHE.put(path, r);
}
return r.getSemVer();
}