/// DrawGViz1
    Useful for drawing small (<100 node) graphs.

    @param PltFNm Output filename (extension .ps, .png, .gif) determines the output format.
    @param NIdColorH Maps node ids to node colors (see GraphViz documentation for more details).
///


/// DrawGViz2
    Useful for drawing small (<100 node) graphs.

    @param PltFNm Output filename (extension .ps, .png, .gif) determines the output format.
    @param NIdColorH Maps node ids to node colors (see GraphViz documentation for more details).
///
