Define the operations that are to be performed on all the nodes that were created or modified within this session. This
class was designed to be as efficient as possible for most nodes, since most nodes do not need any additional processing.
Process the supplied existing node prior to saving the changes but only after the entry corresponding to the key of the
node has been exclusively locked. This method should be implemented as optimal as possible and should only be
needed in multi-threaded scenarios where concurrent modifications may break consistency.