digraph {
    node [shape = "box", style = "filled, rounded"]

    master4[label = "Dirk (today)\nupdates methods chapter", color = limegreen]
    master3[label = "Christian (yesterday)\nfixes typos", color = darkorchid1]
    master2[label = "Dirk (three days ago)\nadds methods chapter", color = limegreen]
    master1[label = "...", color = grey]

    master4 -> master3 -> master2 -> master1
}