code: function hookSyncCycle(rs) {
    if (rs._dropboxOrigSyncCycle) { return; } // already hooked
    rs._dropboxOrigSyncCycle = rs.syncCycle;
    rs.syncCycle = () => {
      if (rs.sync) {
        hookSync(rs);
        rs._dropboxOrigSyncCycle(arguments);
        unHookSyncCycle(rs);
      } else {
        throw new Error('expected sync to be initialized by now');
      }
    };
  }
docs: Hook RemoteStorage.syncCycle as it's the first function called
  after RemoteStorage.sync is initialized, so we can then hook
  the sync function
  @param {object} rs RemoteStorage instance