Why is the answer type is passed to the method as a variable?

So you can't copy-paste everywhere the constructor of the response is transmitted blank. And Yes, not "most" and asynchronous/non-blocking, because in the synchronous classes of responses are primitive and are only used after completion of the response.

This is a project that you must complete. In functional languages this could be the return value, but it is difficult to convey to another asynchronous function. Synthetic example:

asyncSetHeaders(resp)

From a less synthetic example is the need to make an asynchronous request, in order to form a response