code: func (t *TCB) Init(initialSyn header.TCP) Result {
  	t.handlerInbound = synSentStateInbound
  	t.handlerOutbound = synSentStateOutbound
  
  	iss := seqnum.Value(initialSyn.SequenceNumber())
  	t.outbound.una = iss
  	t.outbound.nxt = iss.Add(logicalLen(initialSyn))
  	t.outbound.end = t.outbound.nxt
  
  	// Even though "end" is a sequence number, we don't know the initial
  	// receive sequence number yet, so we store the window size until we get
  	// a SYN from the peer.
  	t.inbound.una = 0
  	t.inbound.nxt = 0
  	t.inbound.end = seqnum.Value(initialSyn.WindowSize())
  	t.state = ResultConnecting
  	return t.state
  }
docs: // Init initializes the state of the TCB according to the initial SYN.