@Override
 public final synchronized void bind(final T value) {
   head.leftShift(value);
   head = (DataFlowStream<T>) head.getRest();
 }
 @Override
 public synchronized String toString() {
   return head.toString();
 }
 @Override
 public final synchronized DataFlowWriteChannel<T> leftShift(final DataFlowReadChannel<T> ref) {
   head.leftShift(ref);
   head = (DataFlowStream<T>) head.getRest();
   return this;
 }