ibute("viewBox", "0 0 10 10");
marker.setAttribute("markerWidth", "2");
marker.setAttribute("markerHeight", "2");
marker.setAttribute("refX", "5");
marker.setAttribute("refY", "5");
marker.setAttribute("markerUnits", "strokeWidth");

var markerPath = createSVGElement("path");
markerPath.setAttribute("fill", "blue");
markerPath.setAttribute("d", "M 5 0 L 10 10 L 0 10 Z");
marker.appendChild(markerPath);

var defsElement = createSVGElement("defs");
defsElement.appendChild(marker);
rootSVGElement.appendChild(d