code: private void handleList(final SecurityContext securityContext, final Writable writable) throws FrameworkException, IOException{
  
  		final Class<NodeInterface> type = StructrApp.getConfiguration().getNodeEntityClass("User");
  		final App app                   = StructrApp.getInstance(securityContext);
  
  		if (type != null) {
  
  			try (final Tx tx = app.tx()) {
  
  				final List<NodeInterface> users = app.nodeQuery(type).sort(AbstractNode.name).getAsList();
  				for (final Iterator<NodeInterface> it = users.iterator(); it.hasNext();) {
  
  					final NodeInterface user = it.next();
  					final String name        = user.getProperty(AbstractNode.name);
  
  					if (name != null) {
  
  						writable.print(name);
  
  					} else {
  
  						writable.print(user.getUuid());
  					}
  
  					if (it.hasNext()) {
  
  						writable.print(", ");
  					}
  				}
  
  				writable.println();
  
  				tx.success();
  			}
  
  		} else {
  
  			throw new FrameworkException(422, "Cannot list users, no User class found.");
  		}
  	}
docs: ----- private methods -----