how can we chain promise together

[takaaptech]

I found lua_promise is awesome lib. The "when" and "done" functions are very clear and easy to use, but how can i chain some promise together? For example, i need some code like this:

promise1 = Promise:new()
promise2 = Promise:new()
promise3 = Promise:new()

promise1:andThen(promise2):andThen(promise3):done()

So when we call promise1:resolve(), it will go next and wait for promise2:resolve() and then wait for promise3:resolve() and finally it call done ?

Thank so much for nice promise lib!