code: function fillMethods(apiObj, urls) {
    const urlKeys = Object.keys(urls);
  
    urlKeys.forEach((urlKey) => {
      const urlVal = urls[urlKey];
  
      if (typeof urlVal === 'string') {
        apiObj[urlKey] = assembleHttp(urlVal);
      } else if (urlVal.url) {
        apiObj[urlKey] = assembleHttp(urlVal);
      } else {
        apiObj[urlKey] = {};
        fillMethods(apiObj[urlKey], urlVal);
      }
    });
  }
docs: 填充方法
  @param  {[type]} apiObj [description]
  @param  {[type]} urls   [description]
  @return {[type]}        [description]