SIPSorcery.SIP.UACInviteTransaction.GetInTransactionACKRequest C# (CSharp) Method

        private SIPRequest GetInTransactionACKRequest(SIPResponse sipResponse, SIPURI ackURI, SIPEndPoint localSIPEndPoint)
        {
            SIPRequest ackRequest = new SIPRequest(SIPMethodsEnum.ACK, ackURI.ToString());
            ackRequest.LocalSIPEndPoint = localSIPEndPoint;

            SIPHeader header = new SIPHeader(TransactionRequest.Header.From, sipResponse.Header.To, sipResponse.Header.CSeq, sipResponse.Header.CallId);
            header.CSeqMethod = SIPMethodsEnum.ACK;
            header.AuthenticationHeader = TransactionRequest.Header.AuthenticationHeader;

            //header.Routes = base.TransactionRequest.Header.Routes;

            header.ProxySendFrom = base.TransactionRequest.Header.ProxySendFrom;

            ackRequest.Header = header;

            SIPViaHeader viaHeader = new SIPViaHeader(localSIPEndPoint, sipResponse.Header.Vias.TopViaHeader.Branch);
            ackRequest.Header.Vias.PushViaHeader(viaHeader);

            return ackRequest;
        }