Optional: Indicates to Eclipse whether to reply to the caller after the transfer has actually happened on both wallets. WHEN_GUARANTEED: Eclipse should reply when the result is guaranteed to happen and will eventually happen, WHEN_COMPLETE: Eclipse should only reply when the source and destination are fully consistent. In all normal situations and by default, WHEN_GUARANTEED should be used. For most wallet transfers between wallets in the same store of value, WHEN_GUARANTEED and WHEN_COMPLETE are identical. WHEN_COMPLETE is only useful when transferring from a digital wallet within Eclipse to a store of value like a card wallet which sits outside of Eclipse. The semantics of these transactions is that the source is debited and the destination is credited in a separate transaction that is retried until success. If the destination wallet is not complete within 5 seconds then Eclipse will reply as if WHEN_GUARANTEED was passed in In order to prevent timeouts on the client.