docs: @Override
      public synchronized Enumeration getSubContextNames() {
          Vector scNames = new Vector();
          for (int i = 0; i < mySubContexts.size(); i++) {
              Entry entry = (Entry) mySubContexts.get(i);
              if (entry.getKey() != null) {
                  scNames.add(entry.getKey());
              }
          }
          return scNames.elements();
      }