                             +. Our account .................................+
+---------+                  +-----+  +--------------+       +---------------+
| Browser |                  | API |  | Object store |       | Virus scanner |
+----+----+                  +--+--+  +------+-------+       +-------+-------+
     | I want to upload         |            |                       |
     | report.pdf               |            |                       |
     +------------------------->#            |                       |
     | upload address, valid 5  #            |                       |
     | min                      #            |                       |
     |<<........................+            |                       |
     | PUT the bytes            |            |                       |
     +--------------------------+----------->#                       |
     | stored                   |            #                       |
     |<<........................+............+                       |
     |                          |            | a new object arrived  |
     |                          |            +---------------------->|
     |                        +- alt [scan passed] ------------------+-+
     |                        | | report.pdf is clean                | |
     |                        | |<-----------+-----------------------+ |
     |                        +. [scan failed] ......................+.+
     |                        | | report.pdf is infected             | |
     |                        | |<===========+=======================+ |
     |                        | | delete it  |                       | |
     |                        | +----------->|                       | |
     |                        +-+------------+-----------------------+-+
     |                          |            |                       |
