code: public void visit(final WebAppServlet webAppServlet) {
  		//CHECKSTYLE:OFF
  		NullArgumentException.validateNotNull(webAppServlet, "Web app servlet");
  		final String[] aliases = webAppServlet.getAliases();
  		if (aliases != null && aliases.length > 0) {
  			for (String alias : aliases) {
  				try {
  					httpService.unregister(alias);
  				} catch (Exception ignore) {
  					LOG.warn("Unregistration exception. Skipping.", ignore);
  				}
  			}
  		} else {
  			LOG.warn("Servlet [" + webAppServlet
  					+ "] does not have any alias. Skipped.");
  		}
  		//CHECKSTYLE:OFF
  	}
docs: Unregisters servlet from http context.
  
  @throws NullArgumentException if servlet is null
  @see WebAppVisitor#visit(WebAppServlet)