(Internal) Plot shadow chart of a single examinee
plotShadowAudit is an internal function for plotting shadow chart of a single examinee, showing all shadowtests over the course of an adaptive test.
plotShadowChart(x, simple, use_par, ...)
x: an output_Shadow object.simple: TRUE simplifies the chart by hiding items that were never used in any shadowtest.use_par: TRUE allows this function to set graphic margins through par....: not used.