Non-blocking - this actually probably makes sense as is.  I wonder if some limited number of other asserts up here would be useful (to assert that it processed the first 10 the first time around vs second time, etc, but it may be redundant because it may be implied.  Up to you.  (You could even refactor some of these asserts into a function that takes the number of events and number of calls, since the same assertions are basically used in every test).  This is not a necessary change though.  :)