/**
   * Splits this filter into two SliceQueryFilters: one that slices only the static columns, and one
   * that slices the remainder of the normal data.
   *
   * <p>This should only be called when the filter is reversed and the filter is known to cover
   * static columns (through hasStaticSlice()).
   *
   * @return a pair of (static, normal) SliceQueryFilters
   */
  public Pair<SliceQueryFilter, SliceQueryFilter> splitOutStaticSlice(CFMetaData cfm) {
    assert reversed;

    Composite staticSliceEnd = cfm.comparator.staticPrefix().end();
    List<ColumnSlice> nonStaticSlices = new ArrayList<>(slices.length);
    for (ColumnSlice slice : slices) {
      if (sliceIncludesStatics(slice, cfm))
        nonStaticSlices.add(new ColumnSlice(slice.start, staticSliceEnd));
      else nonStaticSlices.add(slice);
    }

    return Pair.create(
        new SliceQueryFilter(staticSliceEnd, Composites.EMPTY, true, count, compositesToGroup),
        new SliceQueryFilter(
            nonStaticSlices.toArray(new ColumnSlice[nonStaticSlices.size()]),
            true,
            count,
            compositesToGroup));
  }
  public SliceQueryFilter withUpdatedStart(Composite newStart, CFMetaData cfm) {
    Comparator<Composite> cmp = reversed ? cfm.comparator.reverseComparator() : cfm.comparator;

    // Check our slices to see if any fall before the new start (in which case they can be removed)
    // or
    // if they contain the new start (in which case they should start from the page start).
    // However, if the
    // slices would include static columns, we need to ensure they are also fetched, and so a
    // separate
    // slice for the static columns may be required.
    // Note that if the query is reversed, we can't handle statics by simply adding a separate slice
    // here, so
    // the reversed case is handled by SliceFromReadCommand instead. See CASSANDRA-8502 for more
    // details.
    List<ColumnSlice> newSlices = new ArrayList<>();
    boolean pastNewStart = false;
    for (ColumnSlice slice : slices) {
      if (pastNewStart) {
        newSlices.add(slice);
        continue;
      }

      if (slice.isBefore(cmp, newStart)) {
        if (!reversed && sliceIncludesStatics(slice, cfm))
          newSlices.add(new ColumnSlice(Composites.EMPTY, cfm.comparator.staticPrefix().end()));

        continue;
      } else if (slice.includes(cmp, newStart)) {
        if (!reversed && sliceIncludesStatics(slice, cfm) && !newStart.isEmpty())
          newSlices.add(new ColumnSlice(Composites.EMPTY, cfm.comparator.staticPrefix().end()));

        newSlices.add(new ColumnSlice(newStart, slice.finish));
      } else {
        newSlices.add(slice);
      }

      pastNewStart = true;
    }
    return withUpdatedSlices(newSlices.toArray(new ColumnSlice[newSlices.size()]));
  }