If custom visualization class (NG_Visualization) has been defined. This is the method that gets called if navGraph switches to a graph that links to the visualization class.
如果已定义的自定义可视化类(NG_Visualization)。这是被称为如果navGraph切换到图的方法,可视化类的链接。
See package vignette for more detail.
更多详细信息,请参阅包的小插曲。