An implementation with the following model.
+------------------+
| Transform |
+------------------+
+-----> Instant String +----+
+-----------------+ | | | | +-----------------+
| Source | | | Counter | | | Sink |
+-----------------+ | | | | +-----------------+
| Instant +----+ +------------------+ +----> String |
| | | +------------------+ | | |
| Timer | | | Transform | | | Stdout |
| | | +------------------+ | | |
+-----------------+ +-----> Instant String +----+ +-----------------+
| |
| Elapsed Time |
| |
+------------------+