/usr/include/qxt/QxtNetwork/ is in libqxt-dev 0.6.2-1+b1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/qxt/QxtNetwork/QxtJSONRpcCall
/usr/include/qxt/QxtNetwork/QxtJSONRpcClient
/usr/include/qxt/QxtNetwork/QxtNetwork
/usr/include/qxt/QxtNetwork/QxtRPCPeer
/usr/include/qxt/QxtNetwork/QxtTcpConnectionManager
/usr/include/qxt/QxtNetwork/QxtXmlRpcCall
/usr/include/qxt/QxtNetwork/QxtXmlRpcClient
/usr/include/qxt/QxtNetwork/qxtjsonrpccall.h
/usr/include/qxt/QxtNetwork/qxtjsonrpcclient.h
/usr/include/qxt/QxtNetwork/qxtmail_p.h
/usr/include/qxt/QxtNetwork/qxtmailattachment.h
/usr/include/qxt/QxtNetwork/qxtmailmessage.h
/usr/include/qxt/QxtNetwork/qxtnetwork.h
/usr/include/qxt/QxtNetwork/qxtrpcpeer.h
/usr/include/qxt/QxtNetwork/qxtsmtp.h
/usr/include/qxt/QxtNetwork/qxtsmtp_p.h
/usr/include/qxt/QxtNetwork/qxttcpconnectionmanager.h
/usr/include/qxt/QxtNetwork/qxttcpconnectionmanager_p.h
/usr/include/qxt/QxtNetwork/qxtxmlrpc_p.h
/usr/include/qxt/QxtNetwork/qxtxmlrpccall.h
/usr/include/qxt/QxtNetwork/qxtxmlrpcclient.h