Graphviz 点-如何减少连接两个节点的线

我有一个函数记录在运行时如何调用方法。我正在尝试使用点来可视化这些信息。有些方法被多次调用-例如，在循环的情况下-在图中，我只希望有一条线连接两个节点-是否有一个开关来实现这一点。。。参见示例图“RawFitsData._方法”调用“RawFitsData.init”；多次，在图表中，我只想显示一行

digraph G{
    splines=false;
    ranksep=1;
node[shape=box, color=grey, style=filled];


    "DBProxy.fetch_from_database" -> "RawFitsData._method";
    "RawFitsData._method" -> "RawFitsData.__init__";
    "RawFitsData._method" -> "RawFitsData.__init__";
    "RawFitsData._method" -> "RawFitsData.__init__";
    "RawFitsData._method" -> "RawFitsData.__init__";
 "RawFitsData._method" -> "RawFitsData.__init__";
    "RawFitsData.__init__" -> "RawFitsData._method";
    "RawFitsData._method" -> "RawFitsData.__init__";
    "RawFitsData.__init__" -> "RawFitsData._set_pathname";
    "RawFitsData._set_pathname" ->"split";
    "RawFitsData._set_pathname" ->"setter";
    "RawFitsData.__init__" -> "RawFitsData._get_pathname";
    "RawFitsData._get_pathname" ->"getter";
    "RawFitsData._get_pathname" ->"join";
    "deepcopy" ->"RawFitsData._method";
    "RawFitsData._method" -> "RawFitsData.__reduce__";
    "RawFitsData.__reduce__" -> "WeakValueDictionary.__setitem__";
    "RawFitsData.__reduce__" ->"getter";
    "RawFitsData.__reduce__" -> "RawFitsData._get_pathname";
    "RawFitsData._get_pathname" ->"getter";

    }

使用严格有向图

strict digraph G {
    splines=false;
    ...

它将忽略重复的边。参考文献：