LineCounter.java

    private int binarySearch(final int index)
    {
        return doBinarySearch(0, nrLines - 1, index);
    }

    private int doBinarySearch(final int low, final int high, final int index)
    {
        // Guaranteed to always succeed at this point
        if (low == high)
            return low;

        final int middle = (low + high) / 2;
        final Range<Integer> range = lines.get(middle);
        if (range.contains(index))
            return middle;

        return index < range.lowerEndpoint()
            ? doBinarySearch(low, middle, index)
            : doBinarySearch(middle, high, index);
    }