Checks if the syncronizer is empty
This function is called when the SynchronizationFiber run-function finishes
Recommend to put a yield the SynchronizationFiber between send and receive between the DART's
Stores the add and remove actions in the journal replay log file
This function is called when whole branches doesn't exist in the foreign DART and need to be removed in the local DART
Called in by the SynchronizationFiber constructor which enable the query function to yield the run function in SynchronizationFiber
Interface to the DART synchronizer