docs: function combineFileContent(pkg, toMergeFiles, context) {
      var content = '';
      var has = [];
      var isPackBundles = !! pkg.isPackBundles;
      toMergeFiles.forEach(function (file) {
          has.push(file.id);
          if(isPackBundles){
              if(file.packBundlesTo){
                  fis.log.error('file [%s] has packBundlesTo[%s],can not packBundles more than once!',file.id,pkg.id);
                  return;
              }
              file.packBundlesTo = pkg.subpath;
          }
          // 把要合并的文件的依赖信息添加到打包文件里
          addDependenceResource(pkg, 'addLink', file.links,context);
          addDependenceResource(pkg, 'addRequire', file.requires,context);
          addDependenceResource(pkg, 'addAsyncRequire', file.asyncs,context);
  
          var c;
          if(!isPackBundles && file.packBundlesTo){
              //已经合并在Bundles里面的模块不用打包到pkg里面，只需要pathmap里设置为Bundles文件的moduleId即可
              c = '';
          }else{
              c = file.getContent();
          }
  
          
         /* if (c && file.isCssLike && file !== pkg) {
              c = updateCSSContentUrl(c, file, pkg, context);
          }*/
  
          if (c) {
              if (file.isCssLike) {
                  c = c.replace(CSS_CHARSET_REGEXP, '');
              }
  
              /**
               * @event pack:file 触发打包事件
               */
              fis.emit('pack:file', {
                  file: file,
                  content: c,
                  pkg: pkg
              });
  
              content += c + '\n';
          }
      });
  
      return {
          content: content,
          has: has
      };
  }