Represents a request that has been made. This is normally stored inside the CoapClient and used to find matching responses that come through in the messaging layer.
This allows one to build up a new CoAP request of some form in a method-call-by-method-call manner.
This is returned to the user when he does a finalizing call on a CoapRequestBuilder such as calling post(). The client will then creating the underlying request such that the messaging layer can match a future response to it. The client then sends the CoAP packet and then returns this so-called "future" as a handle to it which can be waited on via a call to get().
The state of a CoapRequestFuture