How to plot candlestick graph with gnuplot_i.hpp in C++

I'm using the gnuplot_i.hpp class to interface with gnuplot https://github.com/tttamaki/gnuplot-cpp/blob/master/gnuplot_i.hpp

I'm not quite sure how you would create a candlestick graph with this class and maybe use the .cmd() function which sends a command to gnuplot. I have two vectors of both open and close prices that I parsed from a .csv file. Anyone know how to do this?