+-----------------+    dummy request     +------------+
|        |        |    with extended     |            |
|        |        |        token         |            |
|    .-<-+->------|=====================>|------.     |
|   _|_           |                      |      |     |
|  /   \ stored   |                      |      |     |
|  \___/ state    |                      |      |     |
|    |            |                      |      |     |
|    '->-+-<------|<=====================|------'     |
|        |        |     response with    |            |
|        |        |    extended token    |            |
|        |        |      echoed back     |            |
|        |        |                      |            |
|        |        |                      |            |
|        |        |     request with     |            |
|        |        |   serialized state   |            |
|        |        |       as token       |            |
|        +--------|=====================>|------.     |
|                 |                      |      |     |
|    look ma,     |                      |      |     |
|    no state!    |                      |      |     |
|                 |                      |      |     |
|        +--------|<=====================|------'     |
|        |        |     response with    |            |
|        v        |   token echoed back  |            |
+-----------------+                      +------------+
      Client                                 Server