final String existingEntry = viaHeaders.get(pv);
if (existingEntry != null) {
return existingEntry;
}
final VersionInfo vi = VersionInfo.loadVersionInfo("org.apache.http.client", getClass().getClassLoader());
final String release = (vi != null) ? vi.getRelease() : VersionInfo.UNAVAILABLE;
String value;
if ("http".equalsIgnoreCase(pv.getProtocol())) {
value = String.format("%d.%d localhost (Apache-HttpClient/%s (cache))", pv.getMajor(), pv.getMinor(),
release);