How to use the fdk.async_http.exceptions.STATUS_CODES.get function in fdk

"Content-Length", len(self.body)
            )

        self.headers["Content-Type"] = self.headers.get(
            "Content-Type", self.content_type
        )

        if self.status in (304, 412):
            self.headers = remove_entity_headers(self.headers)

        headers = self._parse_headers()

        if self.status is 200:
            status = b"OK"
        else:
            status = STATUS_CODES.get(self.status, b"UNKNOWN RESPONSE")

        return (
            b"HTTP/%b %d %b\r\n" b"Connection: %b\r\n" b"%b" b"%b\r\n" b"%b"
        ) % (
            version.encode(),
            self.status,
            status,
            b"keep-alive" if keep_alive else b"close",
            timeout_header,
            headers,
            body,
        )

timeout_header = b""
        if keep_alive and keep_alive_timeout is not None:
            timeout_header = b"Keep-Alive: %d\r\n" % keep_alive_timeout

        self.headers["Transfer-Encoding"] = "chunked"
        self.headers.pop("Content-Length", None)
        self.headers["Content-Type"] = self.headers.get(
            "Content-Type", self.content_type
        )

        headers = self._parse_headers()

        if self.status is 200:
            status = b"OK"
        else:
            status = STATUS_CODES.get(self.status)

        return (b"HTTP/%b %d %b\r\n" b"%b" b"%b\r\n") % (
            version.encode(),
            self.status,
            status,
            timeout_header,
            headers,
        )