LineRect#getRowHeight and LineRect#setRowHeight throw IllegalArgumentException:

 public double getRowHeight(int row) {
        if (row < 0 || row >= cells.length) {
            throw new IllegalArgumentException("Row index '"+row+"' is not within range [0-"+(cells.length-1)+"]");
        }
        
        return cells[row][0].getAnchor().getHeight();
    }
    
    @Override
    public void setRowHeight(int row, final double height) {
        if (row < 0 || row >= cells.length) {
            throw new IllegalArgumentException("Row index '"+row+"' is not within range [0-"+(cells.length-1)+"]");
        }
        ...
}

In both cases, it is more reasonable to throw IndexOutOfBoundsException.