libguide.pdf has an incorrect reference to agopen with only two arguments

Page URL

(https://graphviz.org/pdf/libguide.pdf)

Problem description

libguide.pdf has multiple reference to the agopen subroutine. One of these incorrectly show only 2 arguments.
agopen requires 3 arguments.

correct: Agraph_t* G = agopen(name, type, &disc);
incorrect: g = agopen("g", Agdirected);