Plot a single page.

def plt_goea_results(fout_png, goea_results, *args, **kws):
    """Plot a single page."""
    engine = kws['engine'] if 'engine' in kws else 'pydot'
    godagsmall = OboToGoDagSmall(goea_results=goea_results).godag
    godagplot = GODagSmallPlot(godagsmall, *args, goea_results=goea_results, **kws)
    godagplot.plt(fout_png, engine)