// Python -> LAMMPS
digraph api {
    rankdir="LR";
    python [shape=box style=filled color="#4e9a06" fontcolor=white label="Python\nScript" height=1.5];
    subgraph cluster0 {
      style=filled;
      color="#e5e5e5";
      height=1.5;
      lammps [shape=box style=filled height=1 color="#729fcf" label="lammps\n\nptr: 0x01abcdef"];
      label="LAMMPS Python Module";
    }
    subgraph cluster1 {
      style=filled;
      color="#e5e5e5";
      height=1.5;
      capi [shape=box style=filled height=1 color="#666666" fontcolor=white label="LAMMPS\nC Library API"];
      instance [shape=box style=filled height=1 color="#3465a4" fontcolor=white label="LAMMPS\ninstance\n\n0x01abcdef"];
      capi -> instance [dir=both];
      label="LAMMPS Shared Library";
    }
    python -> lammps [dir=both];
    lammps -> capi [dir=both,label=ctypes];
}