return delegate().setCount(element, count);
      }
    }

    @Override
    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
      synchronized (mutex) {
        return delegate().setCount(element, oldCount, newCount);
      }
    }

    @Override
    public Set<E> elementSet() {
      synchronized (mutex) {
        if (elementSet == null) {

        return delegate().setCount(element, count);
      }
    }

    @Override
    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
      synchronized (mutex) {
        return delegate().setCount(element, oldCount, newCount);
      }
    }

    @Override
    public Set<E> elementSet() {
      synchronized (mutex) {
        if (elementSet == null) {

        return 0;
      }

      int oldCount = values.size();
      if (occurrences >= oldCount) {
        values.clear();
      } else {
        Iterator<V> iterator = values.iterator();
        for (int i = 0; i < occurrences; i++) {
          iterator.next();
          iterator.remove();
        }
      }
      return oldCount;
    }

    @Override
    public void clear() {

        PrintStream oldOut = System.out;
        System.setOut(new PrintStream(systemOut));

        // when
        try {
            cli.cli(cliRequest);
        } catch (MavenCli.ExitException exitException) {
            // expected
        } finally {
            // restore sysout
            System.setOut(oldOut);
        }

     * @param stdout stdout
     * @param stderr stderr
     * @return return code
     */
    public int doMain(String[] args, String workingDirectory, PrintStream stdout, PrintStream stderr) {
        PrintStream oldout = System.out;
        PrintStream olderr = System.err;

        final Set<String> realms;
        if (classWorld != null) {
            realms = new HashSet<>();