code: void checkAllExpectedValues() throws BackendException {
          for (final ExpectedValueCheckingStore store : expectedValuesByStore.keySet()) {
              final Map<KeyColumn, StaticBuffer> m = expectedValuesByStore.get(store);
              for (final KeyColumn kc : m.keySet()) {
                  checkSingleExpectedValue(kc, m.get(kc), store);
              }
          }
      }
docs: Check that all expected values saved from earlier
  {@link KeyColumnValueStore#acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction)}
  calls using this transaction.
  
  @throws com.thinkaurelius.titan.diskstorage.BackendException