[Gnuplot-info] Error in documentation/bug

So, documentation says that we can add latex preamble with tikz terminal 
as *preamble "<preamble string>".*

But this actually does not work, it fails with

/usr/share/gnuplot/6.1/lua/gnuplot-tikz.lua:1773: bad argument #1 to 
'load' (function expected, got string)

Instead of *preamble "<preamble string>" *one should use *preamble 
'<preamble string>' *(single quotes vs double quotes).

I'm not sure if its bug or it's wrong documentation. Below I listed the  
full console output

Thanks!


> $ gnuplot
>
>     G N U P L O T
>     Version 6.1.0 last modified 2025-02-19
>
>     Copyright (C) 1986-1993, 1998, 2004, 2007-2025
>     Thomas Williams, Colin Kelley and many others
>
>     gnuplot home: http://www.gnuplot.info
>     mailing list: gnu...@li...
>     faq, bugs, etc:   type "help FAQ"
>     immediate help:   type "help"  (plot window: hit 'h')
>
>     Terminal type is now qt
> gnuplot> set terminal lua tikz standalone preamble 
> "\usepackage{derivative}"
>
> Terminal type is now 'lua'
>          /usr/share/gnuplot/6.1/lua/gnuplot-tikz.lua:1773: bad 
> argument #1 to 'load' (function expected, got string)
> stack traceb
>
> gnuplot> set terminal lua tikz standalone preamble 
> '\usepackage{derivative}'
>
> Terminal type is now 'lua'
> Options are 'latex preamble "\\usepackage{derivative}"  color 
> standalone nogparrows notikzarrows nogppoints picenvironment 
> nooriginreset bitmap rgbimage noclip notightboundingbox noexternalimages '
> gnuplot>