integer pointed to with \fImsgs_in_queue\fP will contain the number of
remaining messages after this function was called.
+When you fetch a message using this function, it is removed from the internal
+queue so calling this function again will not return the same message
+again. It will instead return new messages at each new invoke until the queue
+is emptied.
+
The data the returned pointer points to will not survive calling
\fIcurl_multi_cleanup(3)\fP or \fIcurl_multi_remove_handle(3)\fP.