Generate a sync message to send to the peer represented by inState
Returns
An array of [newSyncState, syncMessage | null] where
newSyncState should replace inState and syncMessage should be sent to
the peer if it is not null. If syncMessage is null then we are up to date.
Generate a sync message to send to the peer represented by
inStateReturns
An array of
[newSyncState, syncMessage | null]wherenewSyncStateshould replaceinStateandsyncMessageshould be sent to the peer if it is not null. IfsyncMessageis null then we are up to date.