digraph classes {
    graph [rankdir=RL];
    node [shape=rect, style=filled, fontname=Sans, fontsize=10];
    edge [];

    /* Mixin classes */
    node [color="#c69ee0", fontcolor="#000000"]

    

    /* Abstract classes */
    node [color="#9ec6e0", fontcolor="#000000"]

    Device;
    InternalDevice;

    /* Concrete classes */
    node [color="#2980b9", fontcolor="#ffffff"];

    CPUTemperature->PolledInternalDevice;
    DiskUsage->PolledInternalDevice;
    InternalDevice->Device;
    LoadAverage->PolledInternalDevice;
    PingServer->PolledInternalDevice;
    PolledInternalDevice->InternalDevice;
    TimeOfDay->PolledInternalDevice;
}
