SisoDb - New transaction and session behavior

gistfile1.cs

//Behavior today. Everything within the Session is treated as ONE atom transaction.
using(var session = db.BeginSession())
{
    session.Insert(myFoo);
    session.InsertMany(myBars);
    session.Update(mySuperFoo);
}

//Thinking of.... each operation against session is treated as ONE atom operation.
using(var session = db.BeginSession())
{
    session.Insert(myFoo); //Transactional
    session.InsertMany(myBars); //Transactional
    session.Update(mySuperFoo); //Transactional
}

//with the possibility of overruling and get larger scope, e.g

using(var transaction = new SisoTransaction())
{
	using(var session = db.BeginSession())
	{
		session.Insert(myFoo);
		session.InsertMany(myBars);
		session.Update(mySuperFoo);
	}
}