Collection<String> resolvers = ResolverImpl.getDnsServers(); if( resolvers == null ) System.out.println("No DNS servers found."); else {
	public void execute(CommandLine commandLine, InputStream in, PrintStream out, PrintStream err) throws Exception {		ParsedArguments cmdLine = HELP_INFO.parse(commandLine.toStringArray());		    if (cmdLine.size() == 0)	    {	      Collection<String> resolvers = ResolverImpl.getDnsServers();	      if( resolvers == null )	    	  System.out.println("No DNS servers found.");	      else {		      System.out.println("DNS servers");	        for (String dnsServer : resolvers) {	            System.out.println(dnsServer);	        }	      }	    }	    else	    {	      String func = ARG_FUNCTION.getValue(cmdLine);	      IPv4Address server = ARG_DNSSERVER.getAddress(cmdLine);		      if (FUNC_ADD.equals(func))	      {	        ResolverImpl.addDnsServer(server);	      }	      else if (FUNC_DEL.equals(func))	      {	        ResolverImpl.removeDnsServer(server);	      }	    }		    System.out.println();			}