* Construct a version range from a specification.
 *
 */
public class VersionRange {
    private static final Map<String, VersionRange> CACHE_SPEC = Collections.synchronizedMap(new WeakHashMap<>());

    private static final Map<String, VersionRange> CACHE_VERSION = Collections.synchronizedMap(new WeakHashMap<>());

    private final ArtifactVersion recommendedVersion;

    private final List<Restriction> restrictions;

     * @param value the parameter value to store
     */
    public synchronized void putToInfoMap(final String key, final String value) {
        if (infoMap == null) {
            infoMap = Collections.synchronizedMap(new LinkedHashMap<>());
        }
        logger.debug("infoMap: {}={} => {}", key, value, infoMap);
        infoMap.put(key, value);
    }

    /**

    /**
     * Synchronized LRU cache for storing parent URL encodings.
     * Maps session+parent URL keys to their corresponding character encodings.
     */
    Map<String, String> parentEncodingMap = Collections.synchronizedMap(new LruHashMap<>(1000));

    /**
     * Gets the Fess configuration instance.
     *
     * @return the Fess configuration object
     */
    FessConfig getFessConfig();

    /**