Arrow ww = new Arrow("worked_with", "worked with");
new Link(ww, hf, LinkEndStyle.ARROW, null, LinkEndStyle.ARROW, null);
new Link(ww, rs, null, new TextLine("label 1"), null, new TextLine("label 2"));
Diagram d1 = new Diagram("my_diagram", listOf(hf, rs, ww), null);
return d1;
}