How to use the tftpy.TftpContexts.TftpContext function in tftpy

log.debug("TftpContextServer.start() - factory returned a %s", pkt)

        # Call handle once with the initial packet. This should put us into
        # the download or the upload state.
        self.state = self.state.handle(pkt,
                                       self.host,
                                       self.port)

    def end(self):
        """Finish up the context."""
        TftpContext.end(self)
        self.metrics.end_time = time.time()
        log.debug("Set metrics.end_time to %s", self.metrics.end_time)
        self.metrics.compute()

class TftpContextClientUpload(TftpContext):
    """The upload context for the client during an upload.
    Note: If input is a hyphen, then we will use stdin."""
    def __init__(self,
                 host,
                 port,
                 filename,
                 input,
                 options,
                 packethook,
                 timeout,
                 localip = ""):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             localip)

self.host, self.tidport))

        # If there is a packethook defined, call it. We unconditionally
        # pass all packets, it's up to the client to screen out different
        # kinds of packets. This way, the client is privy to things like
        # negotiated options.
        if self.packethook:
            self.packethook(recvpkt)

        # And handle it, possibly changing state.
        self.state = self.state.handle(recvpkt, raddress, rport)
        # If we didn't throw any exceptions here, reset the retry_count to
        # zero.
        self.retry_count = 0

class TftpContextServer(TftpContext):
    """The context for the server."""
    def __init__(self,
                 host,
                 port,
                 timeout,
                 root,
                 dyn_file_func=None,
                 upload_open=None):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             )
        # At this point we have no idea if this is a download or an upload. We
        # need to let the start state determine that.
        self.state = TftpStateServerStart(self)

log.debug("TftpContextServer.start() - factory returned a %s", pkt)

        # Call handle once with the initial packet. This should put us into
        # the download or the upload state.
        self.state = self.state.handle(pkt,
                                       self.host,
                                       self.port)

    def end(self):
        """Finish up the context."""
        TftpContext.end(self)
        self.metrics.end_time = time.time()
        log.debug("Set metrics.end_time to %s", self.metrics.end_time)
        self.metrics.compute()

class TftpContextClientUpload(TftpContext):
    """The upload context for the client during an upload.
    Note: If input is a hyphen, then we will use stdin."""
    def __init__(self,
                 host,
                 port,
                 filename,
                 input,
                 options,
                 packethook,
                 timeout,
                 localip = ""):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             localip)

self.host, self.tidport))

        # If there is a packethook defined, call it. We unconditionally
        # pass all packets, it's up to the client to screen out different
        # kinds of packets. This way, the client is privy to things like
        # negotiated options.
        if self.packethook:
            self.packethook(recvpkt)

        # And handle it, possibly changing state.
        self.state = self.state.handle(recvpkt, raddress, rport)
        # If we didn't throw any exceptions here, reset the retry_count to
        # zero.
        self.retry_count = 0

class TftpContextServer(TftpContext):
    """The context for the server."""
    def __init__(self,
                 host,
                 port,
                 timeout,
                 root,
                 dyn_file_func=None,
                 upload_open=None):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             )
        # At this point we have no idea if this is a download or an upload. We
        # need to let the start state determine that.
        self.state = TftpStateServerStart(self)

if self.retry_count >= TIMEOUT_RETRIES:
                    log.debug("hit max retries, giving up")
                    raise
                else:
                    log.warning("resending last packet")
                    self.state.resendLast()

    def end(self):
        """Finish up the context."""
        TftpContext.end(self)
        self.metrics.end_time = time.time()
        log.debug("Set metrics.end_time to %s" % self.metrics.end_time)
        self.metrics.compute()


class TftpContextClientDownload(TftpContext):
    """The download context for the client during a download.
    Note: If output is a hyphen, then the output will be sent to stdout."""
    def __init__(self,
                 host,
                 port,
                 filename,
                 output,
                 options,
                 packethook,
                 timeout,
                 localip = ""):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             localip)

if self.retry_count >= TIMEOUT_RETRIES:
                    log.debug("hit max retries, giving up")
                    raise
                else:
                    log.warning("resending last packet")
                    self.state.resendLast()

    def end(self):
        """Finish up the context."""
        TftpContext.end(self)
        self.metrics.end_time = time.time()
        log.debug("Set metrics.end_time to %s" % self.metrics.end_time)
        self.metrics.compute()


class TftpContextClientDownload(TftpContext):
    """The download context for the client during a download.
    Note: If output is a hyphen, then the output will be sent to stdout."""
    def __init__(self,
                 host,
                 port,
                 filename,
                 output,
                 options,
                 packethook,
                 timeout,
                 localip = ""):
        TftpContext.__init__(self,
                             host,
                             port,
                             timeout,
                             localip)