
case the test results will be plotted. <code>"boxplot"</code> results in boxplots across all observations/iterations of either
the bootstrap or training/test re-fitting. For the latter
case the test results will be plotted. <code>"interaction"</code> creates an
interaction plot for the different subgroups (crossing lines here means a meaningful subgroup). For the interaction plot,
the intervals around each point represent +1 one SE
<code>"conditional"</code> For subgroup_fitted objects, plots smoothed (via