/**
* Fills a List with all sister-targets of a single target
* @return filled or empty List
*/
private ArrayList getCoTargets (ACSTargetElement aTarget) {
ACSProjectElement parentProject = null;
// Caution is the mother of wisdom ;-)
if (aTarget.getParentNode() instanceof ACSProjectElement)
parentProject = (ACSProjectElement) aTarget.getParentNode();
else throw new IllegalArgumentException("Target not part of Project");
DOMNodeList allNodes = parentProject.getChildNodes();
ArrayList retVal = new ArrayList();
int length = allNodes.getLength();
for (int i = 0; i < length; i++) {
DOMNode node = allNodes.item(i);
if (node instanceof ACSTargetElement) {