/** {@inheritDoc} */
 @Override
 public <V> V putMetaIfAbsent(String name, Callable<V> c) {
   return tx.putMetaIfAbsent(name, c);
 }
 /** {@inheritDoc} */
 @Override
 public <V> V putMetaIfAbsent(String name, V val) {
   return tx.putMetaIfAbsent(name, val);
 }