@Override
    public void registerProxyTransfer(String transferDigest, ProxyTransfer proxyTransfer)
            throws UnauthorizedException
    {
        FileTransfer transfer = retrieveFileTransfer(transferDigest);
        if (isMatchProxyTransfer() && transfer == null) {
            throw new UnauthorizedException("Unable to match proxy transfer with a file transfer");
        }
        else if (transfer == null) {
            return;
        }

        transfer.setProgress(proxyTransfer);
        cacheFileTransfer(transferDigest, transfer);
    }
Returns true if the proxy transfer should be matched to an existing file transfer
in the system.

@return Returns true if the proxy transfer should be matched to an existing file
transfer in the system.
xmppserver/src/main/java/org/jivesoftware/openfire/filetransfer/DefaultFileTransferManager.java