$ GET /chat/stream?message=hello world   (raw lines, first 14 and last 5)
event:token
data: [stub]

event:token
data:  saw

event:token
data:  2

event:token
data:  messages.

event:token
data:  Earlier
...
data:  world
<blank>
event:done
data:
<blank>
event names seen: [token, done]
joined token text as EventSource delivers it: [stub] saw 2 messages. Earlier user turns: none. You said: hello world
same text if the server did not pad:        [stub]saw2messages.Earlieruserturns:none.Yousaid:helloworld