anchor.diff:   */
   String BUILD_ID = null;
   
  -typedef void HandleOption(String option);
  +/**
  + * The data passed to the [HandleOption] callback is either a single
  + * string argument, or the arguments iterator for multiple arguments
  + * handlers.
  + */
  +typedef void HandleOption(data);
   
   class OptionHandler {
  -  String pattern;
  -  HandleOption handle;
  -
  -  OptionHandler(this.pattern, this.handle);
  +  final String pattern;
  +  final HandleOption handle;
  +  final bool multipleArguments;
  +
  +  OptionHandler(this.pattern, this.handle, {this.multipleArguments: false});
   }
   
   /**
  
positive.code: Compiles Dart to JavaScript.
  
  Supported options:
    -o<file>, --out=<file>
      Generate the output into <file>.
  
    -c, --enable-checked-mode, --checked
  
negative.code:     new OptionHandler('--verbose', setVerbose),
      new OptionHandler('--version', (_) => wantVersion = true),
      new OptionHandler('--library-root=.+', setLibraryRoot),
      new OptionHandler('--out=.+|-o.*', setOutput, multipleArguments: true),
      new OptionHandler('--allow-mock-compilation', passThrough),
      new OptionHandler('--minify', passThrough),
      new OptionHandler('--force-strip=.*', setStrip),
  