(node:10912) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'then' of undefined
    at getPostData.then.postdata (E:\nodejs\blog-2\app.js:45:35)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:10912) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:10912) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

模仿blog1的书写事，在运行时出现这个问题，定位在下面红色款内，提示then这个属性没有定义，研究了很久也没发现问题所在，希望老师有空帮忙看看解答下

这个方法在blog文件这样写的、
还是把getBlogList方法跟exec方法的图片也贴上吧