private Iterable<List<Object>> buildCartesianProduct(Set<?>... sets) {
    List<Set<Optional<?>>> optionalSets = Lists.newArrayListWithExpectedSize(sets.length);
    for (Set<?> set : sets) {
      Set<Optional<?>> optionalSet =
          Sets.newLinkedHashSet(Iterables.transform(set, NULLABLE_TO_OPTIONAL));
      optionalSets.add(optionalSet);
    }
    Set<List<Optional<?>>> cartesianProduct = Sets.cartesianProduct(optionalSets);

      if (set.isEmpty()) {
        /*
         * The (tooLow + 1, tooHigh) arguments below would be invalid because tooLow would be
         * greater than tooHigh.
         */
        return ContiguousSet.create(Range.openClosed(0, 1), DiscreteDomain.integers()).subSet(0, 1);
      }
      int tooHigh = set.last() + 1;
      int tooLow = set.first() - 1;
      set.add(tooHigh);

    private int mode;
    private long offset;

    /**
     * Sets the file identifier.
     *
     * @param fid
     *            the fid to set
     */
    public void setFid(final int fid) {
        this.fid = fid;
    }

    /**
     * Sets the seek mode.
     *
     * @param mode
     *            the mode to set
     */
    public final void setMode(final int mode) {
        this.mode = mode;

        this.fileId = fileId;
    }

    /**
     * Sets the information type for the set info operation
     *
     * @param infoType
     *            the infoType to set
     */
    public void setInfoType(final byte infoType) {
        this.infoType = infoType;
    }

    /**
     * Sets the file information class for the set info operation
     *
     * @param fileInfoClass

            return false;
        }
        return true;
    }

    /**
     * Returns a set of matched label values.
     *
     * @param path The path to match.
     * @return A set of matched label values.
     */
    public Set<String> getMatchedLabelValueSet(final String path) {
        if (labelTypePatternList == null) {
            synchronized (this) {

        }
        return pageSize;
    }

    /**
     * Sets the number of records to display per page.
     *
     * @param pageSize The page size to set
     */
    public void setPageSize(final int pageSize) {
        this.pageSize = pageSize;
    }

    /**
     * Gets the current page number (1-based).
     * If not set or invalid, returns the default current page number.
     *

    }

    /**
     * Gets the total number of records in the result set.
     *
     * @return the total record count
     */
    public int getAllRecordCount() {
        return allRecordCount;
    }

    /**
     * Sets the total number of records in the result set.
     *
     * @param allRecordCount the total record count to set
     */
    public void setAllRecordCount(final int allRecordCount) {

    }

    /**
     * Sets the file information class for the directory query
     *
     * @param fileInformationClass
     *            the fileInformationClass to set
     */
    public void setFileInformationClass(final byte fileInformationClass) {
        this.fileInformationClass = fileInformationClass;
    }

    /**
     * Sets the query flags for the directory enumeration
     *

    }

    /**
     * Gets the total number of records in the result set.
     *
     * @return the total record count
     */
    public int getAllRecordCount() {
        return allRecordCount;
    }

    /**
     * Sets the total number of records in the result set.
     *
     * @param allRecordCount the total record count
     */

    assertEquals(set.comparator(), copy.comparator());
  }

  @GwtIncompatible // SerializableTester
  public void testSeveral_serialization() {
    SortedSet<String> set = new SafeTreeSet<>();
    set.add("a");
    set.add("b");
    set.add("c");
    SortedSet<String> copy = SerializableTester.reserializeAndAssert(set);
    assertEquals(set.comparator(), copy.comparator());
  }