digraph "Hashmap's data structure" {

    label="HashMap module data structure";
    compound=true;

    compute;
    network [label="network.floating_ip"];
    volume;

    subgraph cluster_0 {
        label="services";
        style=dashed;
        {rank=same; compute -> network -> volume [style=invis];}
    }

    compute -> flavor;

    subgraph cluster_1 {
        label="fields:\nAssociate to metadata";
        style=dashed;
        flavor;
    }

    // Mappings
    micro [label="value=m1.micro\ntype=flat\ncost=0.1"];
    tiny [label="value=m1.tiny\ntype=flat\ncost=0.2"];
    small [label="value=m1.small\ntype=flat\ncost=0.4"];

    floating [label="\ntype=flat\ncost=0.5"];

    // Thresholds
    1024 [label="level=1024\ntype=flat\ncost=0.1"];
    10240 [label="level=10240\ntype=flat\ncost=0.2"];

    subgraph cluster_2 {
        label="mappings";
        style=dashed;
        {rank=same; micro -> tiny -> small -> floating [style=invis];}
    }

    subgraph cluster_3 {
        label="thresholds";
        style=dashed;
        {rank=same; 1024 -> 10240 [style=invis];}
    }

    flavor -> micro;
    flavor -> tiny;
    flavor -> small;
    network -> floating;
    volume -> 1024;
    volume -> 10240;
}