public Object getParent(Object element) {
   if (element instanceof PropertiesTreeData) {
     PropertiesTreeData data = (PropertiesTreeData) element;
     return data.getFile();
   }
   return null;
 }
 @Override
 public String getDescription(Object anElement) {
   if (anElement instanceof PropertiesTreeData) {
     PropertiesTreeData data = (PropertiesTreeData) anElement;
     return "Property: " + data.getName(); // $NON-NLS-1$
   }
   return null;
 }
 @Override
 public String getText(Object element) {
   if (element instanceof PropertiesTreeData) {
     PropertiesTreeData data = (PropertiesTreeData) element;
     return data.getName() + "= " + data.getValue(); // $NON-NLS-1$
   }
   return null;
 }