docs: @Override
      public void selectionChanged(IAction action, ISelection selection) {
  
          bugInstance = null;
          // TODO learn to deal with ALL elements
          IMarker markerFromSelection = MarkerUtil.getMarkerFromSingleSelection(selection);
          marker = markerFromSelection;
  
          if (marker == null) {
              // No marker selected.
              return;
          }
          if (DEBUG) {
              System.out.println("Found a marker!");
          }
  
          bugInstance = MarkerUtil.findBugInstanceForMarker(marker);
          if (bugInstance != null) {
              if (DEBUG) {
                  System.out.println("Found BugInstance for SpotBugs warning marker!");
              }
          }
      }