data=iris[,-5]
exact_grouping=list(which(iris[,5]=="setosa"),
                    which(iris[,5]=="versicolor"),
                    which(iris[,5]=="virginica"))

grouping=list(c(1:40),c(41:90),c(91:150))
k=3
centers=rbind(c(1,2,3,4),c(2,3,4,5),c(4,5,6,7))


test_that("ClustPlot", {
  graff=ClustPlot(data, grouping, exact_grouping,centers, k)
  expect_s3_class(graff, "ggplot")
})