digraph Conversions {
    rankdir=LR
    CppType1 [ label="C++\nType" ]
    Converter1 [ label="Converter\nPython -> C++", shape=hexagon ]
    PythonType1 -> Converter1
    PythonType2 -> Converter1
    PythonType3 -> Converter1
    Converter1 -> CppType1

    CppType2 [ label="C++\nType" ]
    PythonType4 [ label="PythonType" ]
    Converter2 [ label="Converter\nPython -> C++", shape=hexagon ]
    CppType2 -> Converter2 -> PythonType4
}