digraph G {
    compound="true"
    rankdir="TB"
    bgcolor="white"
    fontname="Tahoma"

    node [
        fixedsize="false"
        fontname="Tahoma"
        color="white"
        fillcolor="grey"
        fontcolor="black"
        shape="box"
        style="filled"
        penwidth="1.0"
    ]
    edge [
        fontname="Arial"
        color="#00688b"
        fontcolor="black"
        fontsize="12"
        arrowsize="0.5"
        penwidth="1.0"
    ]

    "orderbook-sample" [fillcolor="deepskyblue2"];
    "orderbook-core" [fillcolor="deepskyblue2"];
    "orderbook-benchmark" [fillcolor="deepskyblue2"];
    "orderbook-it" [fillcolor="deepskyblue2"];



    "orderbook-benchmark" -> "orderbook-core" [label=" 7 ", penwidth="7", color="#00688bC9"];
    "orderbook-sample" -> "orderbook-core" [label=" 4 ", penwidth="4", color="#00688b93"];
    "orderbook-it" -> "orderbook-core" [label=" 1 ", penwidth="1", color="#00688b5E"];

}