private void tapAck(TapConnectionProvider conn, MemcachedNode node,
      TapOpcode opcode, int opaque, OperationCallback cb) {
    final Operation op = conn.getOpFactory().tapAck(opcode, opaque, cb);
    conn.addTapAckOp(node, op);
  }
Specifies a tap stream that will take a snapshot of items in memcached and
send them through a tap stream.

@param id the named tap id that can be used to resume a disconnected tap
         stream
@return the operation that controls the tap stream.
@throws ConfigurationException a bad configuration was received from the
          memcached cluster.
@throws IOException If there are errors connecting to the cluster.
src/main/java/net/spy/memcached/TapClient.java