@startuml

box "browser"
actor Caller
database Cache
control Observable
end box
entity ByzCoin

Caller -> Observable: user.coinBS.subscribe((coin) =>\nconsole.log(coin.value))
Observable -> Observable: console: 10000

Caller -> Caller: const tx = \nuser.startTransaction()
Caller -> Caller: user.coinBS.transferCoins(\ntx, destID, Long.from(1000))
Caller -> ByzCoin: tx.sendCoins()
activate ByzCoin

ByzCoin -> ByzCoin: verify transaction and create block
ByzCoin -> ByzCoin: update the global state
ByzCoin -> Cache: new block available
deactivate ByzCoin

Cache -> ByzCoin: send ID of all known instances
ByzCoin -> Cache: changed instances

Cache -> Cache: update instances
Cache -> Observable: new value available

Observable -> Observable: console: 9000

@enduml