while (peekingItr.hasNext()) {
          Range<C> nextRange = peekingItr.peek();
          if (range.isConnected(nextRange)) {
            checkArgument(
                range.intersection(nextRange).isEmpty(),
                "Overlapping ranges not permitted but found %s overlapping %s",
                range,
                nextRange);
            range = range.span(peekingItr.next());
          } else {

        while (peekingItr.hasNext()) {
          Range<C> nextRange = peekingItr.peek();
          if (range.isConnected(nextRange)) {
            checkArgument(
                range.intersection(nextRange).isEmpty(),
                "Overlapping ranges not permitted but found %s overlapping %s",
                range,
                nextRange);
            range = range.span(peekingItr.next());
          } else {

          }
          Range<C> nextRange = completeRangeItr.next();
          if (restriction.lowerBound.compareTo(nextRange.upperBound) >= 0) {
            return endOfData();
          }
          nextRange = nextRange.intersection(restriction);
          if (lowerBoundWindow.contains(nextRange.lowerBound)) {
            return Maps.immutableEntry(nextRange.lowerBound, nextRange);
          } else {