anchor.diff:  import 'package:analyzer/src/generated/sdk.dart';
   import 'package:analyzer/src/generated/sdk_io.dart';
   import 'package:args/args.dart';
  -import 'package:logging/logging.dart';
   
   /**
    * The [Driver] class represents a single running instance of the analysis
  
positive.code:    */
    void start(List<String> args) {
      ArgParser parser = new ArgParser();
      parser.addFlag(HELP_OPTION, help:
          "print this help message without starting a server", defaultsTo: false,
          negatable: false);
      parser.addOption(PORT_OPTION, help:
          "[port] the port on which the server will listen");
      parser.addOption(LOG_FILE_OPTION, help:
          "[path] file to log debugging messages to");
      parser.addOption(SDK_OPTION, help:
          "[path] path to the sdk");
  
      ArgResults results = parser.parse(args);
      if (results[HELP_OPTION]) {
        _printUsage(parser);
        return;
      }
      if (results[LOG_FILE_OPTION] != null) {
        try {
          File file = new File(results[LOG_FILE_OPTION]);
          IOSink sink = file.openWrite();
          Logger.root.onRecord.listen((LogRecord record) {
            sink.writeln(record);
          });
        } catch (exception) {
          print('Could not open log file: $exception');
          exitCode = 1;
          return;
        }
      }
      int port;
  
negative.code:   static const BINARY_NAME = 'server';
  
    /**
     * The name of the option used to enable instrumentation.
     */
    static const String ENABLE_INSTRUMENTATION_OPTION = "enable-instrumentation";
  
    /**
     * The name of the option used to print usage information.
     */
    static const String HELP_OPTION = "help";
  
    /**
     * The name of the option used to specify the log file to which
     * instrumentation data is to be written.
     */
    static const String INSTRUMENTATION_LOG_FILE_OPTION = "instrumentation-log-file";
  
    /**
     * The name of the option used to specify the port to which the server will
     * connect.
     */
    static const String PORT_OPTION = "port";
  
    /**
     * The path to the SDK.
  