* @see edu.indiana.extreme.xbaya.graph.GraphFactory#createEdge(org.xmlpull.infoset.XmlElement)
*/
public EdgeImpl createEdge(XmlElement edgeElement) {
String type = edgeElement.attributeValue(GraphSchema.NS,
GraphSchema.EDGE_TYPE_ATTRIBUTE);
EdgeImpl edge;
if (GraphSchema.EDGE_TYPE_DATA.equals(type)) {
edge = new DataEdge(edgeElement);
} else if (GraphSchema.PORT_TYPE_CONTROL.equals(type)) {
edge = new ControlEdge(edgeElement);
} else {