Service(otherSide: Party, timestampChecker: TimestampChecker, uniquenessProvider: UniquenessProvider)
A flow run by a notary service that handles notarisation requests.
It checks that the timestamp command is valid (if present) and commits the input state, or returns a conflict if any of the input states have been previously committed.
Additional transaction validation logic can be added when implementing receiveAndVerifyTx.