library(directlabels)
library(testthat)
if(require(lattice)){
  test_that("panel.superpose.dl works", {
    loci <- data.frame(
      ppp=c(rbeta(8,10,10),rbeta(2,0.15,1),rbeta(2,1,0.15)),
      type=factor(c(rep("NEU",8),rep("POS",2),rep("BAL",2))))
    direct.label(densityplot(~ppp,loci,groups=type,n=500))
    computed <- suppressWarnings(with(loci, panel.superpose.dl(
      x=ppp, groups = type, subscripts=seq_along(ppp),
      method="top.bumptwice", panel.groups="panel.densityplot")))
    expect_identical(computed, NULL)
  })
}