code: function load(type, id, path, callback, req) {
    let filter = null;
    try {
      let file = path + '.js';
      filter = require(file);
      delete require.cache[require.resolve(file)];
    } catch (ex) {
      // ignore
    }
  
    // 如果filter是个json对象
    if (filter && (typeof filter !== 'function')) {
      return callback(filter);
    }
  
    getFromNEISite(type, id, function (json) {
      if (json == null) {
        try {
          let file = path + '.json';
          console.log(`Mock数据为本地JSON文件: ${file}`);
          json = require(file);
          delete require.cache[require.resolve(file)];
        } catch (ex) {
          // ignore
        }
      }
  
      if (filter) {
        json = filter(json, req);
      }
  
      callback(json);
    }, req);
  }
docs: 加载数据