code: public RESTCatalog describeCommands() {
          Map<String, SortedMap<String, RESTCommand>> ownerMap = new HashMap<>(m_cmdsByOwnerMap);
          for (String cmdOwner : ownerMap.keySet()) {
              SortedMap<String, RESTCommand> cmdMap = ownerMap.get(cmdOwner);
              Iterator<RESTCommand> iter = cmdMap.values().iterator();
              while (iter.hasNext()) {
                  if (!iter.next().isVisible()) {
                      iter.remove();
                  }
              }
          }
          return new RESTCatalog(ownerMap);
      }
docs: Describe the current set of visible, registered commands in a {@link RESTCatalog}
  object.
  
  @return  A copy of visible, registered commands as a {@link RESTCatalog}.