How to use the waitress.buffers.OverflowableBuffer function in waitress

def _makeOne(self, overflow=10):
        from waitress.buffers import OverflowableBuffer

        buf = OverflowableBuffer(overflow)
        self.buffers_to_close.append(buf)
        return buf

def write_soon(self, data):
        if data:
            # the async mainloop might be popping data off outbuf; we can
            # block here waiting for it because we're in a task thread
            with self.outbuf_lock:
                if data.__class__ is ReadOnlyFileBasedBuffer:
                    # they used wsgi.file_wrapper
                    self.outbufs.append(data)
                    nextbuf = OverflowableBuffer(self.adj.outbuf_overflow)
                    self.outbufs.append(nextbuf)
                else:
                    self.outbufs[-1].append(data)
            # XXX We might eventually need to pull the trigger here (to
            # instruct select to stop blocking), but it slows things down so
            # much that I'll hold off for now; "server push" on otherwise
            # unbusy systems may suffer.
            return len(data)
        return 0

self.url_scheme = self.adj.url_scheme
        connection = headers.get('CONNECTION', '')

        if version == '1.0':
            if connection.lower() != 'keep-alive':
                self.connection_close = True

        if version == '1.1':
            # since the server buffers data from chunked transfers and clients
            # never need to deal with chunked requests, downstream clients
            # should not see the HTTP_TRANSFER_ENCODING header; we pop it
            # here
            te = headers.pop('TRANSFER_ENCODING', '')
            if te.lower() == 'chunked':
                self.chunked = True
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = ChunkedReceiver(buf)
            expect = headers.get('EXPECT', '').lower()
            self.expect_continue = expect == '100-continue'
            if connection.lower() == 'close':
                self.connection_close = True

        if not self.chunked:
            try:
                cl = int(headers.get('CONTENT_LENGTH', 0))
            except ValueError:
                cl = 0
            self.content_length = cl
            if cl > 0:
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = FixedStreamReceiver(cl, buf)

self.chunked = True
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = ChunkedReceiver(buf)
            expect = headers.get('EXPECT', '').lower()
            self.expect_continue = expect == '100-continue'
            if connection.lower() == 'close':
                self.connection_close = True

        if not self.chunked:
            try:
                cl = int(headers.get('CONTENT_LENGTH', 0))
            except ValueError:
                cl = 0
            self.content_length = cl
            if cl > 0:
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = FixedStreamReceiver(cl, buf)

)

            expect = headers.get("EXPECT", "").lower()
            self.expect_continue = expect == "100-continue"
            if connection.lower() == "close":
                self.connection_close = True

        if not self.chunked:
            try:
                cl = int(headers.get("CONTENT_LENGTH", 0))
            except ValueError:
                raise ParsingError("Content-Length is invalid")

            self.content_length = cl
            if cl > 0:
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = FixedStreamReceiver(cl, buf)

for encoding in encodings:
                # Out of the transfer-codings listed in
                # https://tools.ietf.org/html/rfc7230#section-4 we only support
                # chunked at this time.

                # Note: the identity transfer-coding was removed in RFC7230:
                # https://tools.ietf.org/html/rfc7230#appendix-A.2 and is thus
                # not supported
                if encoding not in {"chunked"}:
                    raise TransferEncodingNotImplemented(
                        "Transfer-Encoding requested is not supported."
                    )

            if encodings and encodings[-1] == "chunked":
                self.chunked = True
                buf = OverflowableBuffer(self.adj.inbuf_overflow)
                self.body_rcv = ChunkedReceiver(buf)
            elif encodings:  # pragma: nocover
                raise TransferEncodingNotImplemented(
                    "Transfer-Encoding requested is not supported."
                )

            expect = headers.get("EXPECT", "").lower()
            self.expect_continue = expect == "100-continue"
            if connection.lower() == "close":
                self.connection_close = True

        if not self.chunked:
            try:
                cl = int(headers.get("CONTENT_LENGTH", 0))
            except ValueError:
                raise ParsingError("Content-Length is invalid")

def __init__(
            self,
            server,
            sock,
            addr,
            adj,
            map=None,
            ):
        self.server = server
        self.adj = adj
        self.outbufs = [OverflowableBuffer(adj.outbuf_overflow)]
        self.creation_time = self.last_activity = time.time()

        # task_lock used to push/pop requests
        self.task_lock = threading.Lock()
        # outbuf_lock used to access any outbuf
        self.outbuf_lock = threading.Lock()

        asyncore.dispatcher.__init__(self, sock, map=map)

        # Don't let asyncore.dispatcher throttle self.addr on us.
        self.addr = addr