code: function (callback, source, dest)
      {
          compressor.compress(
              // Source can either be a file path or source code 
              source,
              // Options
              {
                  charset: 'utf8',
                  type: 'js',
                  nomunge: true,
                  'preserve-semi': true
              },
              // Compressor callback
              function (error, data, extra)
              {
                  if (error)
                  {
                      grunt.warn(error);
                      return callback();
                  }
  
                  if (extra)
                      grunt.log.writeln(extra);
  
                  grunt.file.write(dest, data);
                  callback();
              }
          );
      }
docs: Minifies the passed extendscript files using YUI.