* are identical, even if the input set uses a different concept of equivalence.
   *
   * <p><i>Performance notes:</i> while the power set of a set with size {@code n} is of size {@code
   * 2^n}, its memory usage is only {@code O(n)}. When the power set is constructed, the input set
   * is merely copied. Only as the power set is iterated are the individual subsets created, and

    }


    /**
     * @return session increased usage count
     */
    public SmbSessionImpl acquire () {
        long usage = this.usageCount.incrementAndGet();
        if ( log.isTraceEnabled() ) {
            log.trace("Acquire session " + usage + " " + this);
        }

        if ( usage == 1 ) {
            synchronized ( this ) {

   * if the primary input succeeds, it is never invoked. If, during the invocation of {@code
   * fallback}, an exception is thrown, this exception is used as the result of the output {@code
   * Future}.
   *
   * <p>Usage example:
   *
   * <pre>{@code
   * ListenableFuture<Integer> fetchCounterFuture = ...;
   *
   * // Falling back to a zero counter in case an exception happens when
   * // processing the RPC to fetch counters.

 * <code>java.io.File</code> usage; a '/' at the beginning of the second
 * parameter will still use the server component of the first parameter. The
 * examples below illustrate the resulting URLs when this second constructor
 * argument is used.
 *
 * <p>
 * <table border="1" cellpadding="3" cellspacing="0" width="100%" summary="Usage examples">
 * <tr bgcolor="#ccccff">
 * <td colspan="3">

                            Severity.WARNING,
                            Version.V31,
                            prefix + prefix2 + "scope",
                            key,
                            "declares usage of deprecated 'system' scope ",
                            dependency);
                }

                String sysPath = dependency.getSystemPath();
                if (sysPath != null && !sysPath.isEmpty()) {

    @Override
    public String toString () {
        return super.toString() + "[" + this.address + ":" + this.port + ",state=" + this.state + ",signingEnforced=" + this.signingEnforced
                + ",usage=" + this.getUsageCount() + "]";
    }


    /* DFS */
    @Override

 * </ul>
 *
 * <p>These features are all optional; caches can be created using all or none of them. By default,
 * cache instances created by {@code CacheBuilder} will not perform any type of eviction.
 *
 * <p>Usage example:
 *
 * <pre>{@code
 * LoadingCache<Key, Graph> graphs = CacheBuilder.newBuilder()
 *     .maximumSize(10000)
 *     .expireAfterWrite(Duration.ofMinutes(10))
 *     .removalListener(MY_LISTENER)