/// <summary>
/// Attempts to get a SessionVector by ID. If it doesn't exist then there's a chance that
/// we're out-of-sync. So go to the cluster and look for a session by that ID. If one
/// exists then start a local session with that ID and the details stored in the cluster.
/// </summary>
/// <param name="sessionId"></param>
/// <returns></returns>
public Option <SessionVector> GetSession(SessionId sessionId) =>
Sync.GetSession(sessionId).IfNone(() =>
Sync.GetSession(from c in cluster
from ts in c.GetHashField <long>(SessionKey(sessionId), LastAccessKey)
from to in c.GetHashField <int>(SessionKey(sessionId), TimeoutKey)
select Sync.Start(sessionId, to, LoadData(sessionId)))
.IfNone(() => failwith <SessionVector>("Session doesn't exist")));
/// <summary>
/// Attempts to get a SessionVector by ID. If it doesn't exist then there's a chance that
/// we're out-of-sync. So go to the cluster and look for a session by that ID. If one
/// exists then start a local session with that ID and the details stored in the cluster.
/// </summary>
/// <param name="sessionId"></param>
/// <returns></returns>
public Option <SessionVector> GetSession(SessionId sessionId) =>
Sync.GetSession(sessionId) || Sync.GetSession(from c in cluster
from to in c.GetHashField <int>(SessionKey(sessionId), TimeoutKey)
select Sync.Start(sessionId, to));