final int startPosition = params.getStartPosition();
        if (startPosition * 2 >= windowSize) {
            int offset = params.getOffset();
            if (offset < 0) {
                offset = 0;
            } else if (offset > windowSize / 2) {
                offset = windowSize / 2;
            }
            int start = startPosition - offset;
            if (start < 0) {