Also, the Subscribe ScalaDoc was written as a specification / requirement, using "shall". This is unusually formal, and is difficult to read. For example, the sentence:

"An empty payload of length zero shall subscribe to all incoming messages"

probably means that providing a zero-length string as an argument to the apply method acts as a completely open filter, and causes all received messages to be accepted. The sentence is especially awkward because the reader has to realize that the writer probably did not intend to say that payloads subscribe, but instead the writer meant that the apply method's argument acts as a filter.

"Multiple filters may be attached to a single akka.zeromq.SocketType.Sub socket, in which case a message shall be accepted if it matches at least one filter." This sentence leaves a lot to the imagination. If a Subscribe is a filter, then perhaps newSocket() can accept a collection of Subscribe; otherwise perhaps there is a syntax to use for the apply() method's argument. The comment for the apply() method suggests that this is not the case because 'topic' is expressed in the singular. The reader is left bewildered.

Updating tickets (#2186, #2187, #2189, #2192, #2196, #2197, #2198, #2200, #2203, #2208, #2212, #2217, #2218, #2221, #2224, #2225, #2226, #2227, #2228, #2232, #2236, #2237, #2247, #2248, #2255, #2257, #2260, #2262, #2268, #2269, #2272, #2276, #2285, #2288, #2292, #2294, #2295, #2298, #2301, #2302, #2312, #2315, #2318, #2319, #2332, #2333, #2335, #2337, #2340, #2341, #2342, #2345)