How to use the gunicorn._compat.bytes_to_str function in gunicorn

def parse_headers(self, data):
        cfg = self.cfg
        headers = []

        # Split lines on \r\n keeping the \r\n on each line
        lines = [bytes_to_str(line) + "\r\n" for line in data.split(b"\r\n")]

        # handle scheme headers
        scheme_header = False
        secure_scheme_headers = {}
        if '*' in cfg.forwarded_allow_ips:
            secure_scheme_headers = cfg.secure_scheme_headers
        elif isinstance(self.unreader, SocketUnreader):
            remote_addr = self.unreader.sock.getpeername()
            if isinstance(remote_addr, tuple):
                remote_host = remote_addr[0]
                if remote_host in cfg.forwarded_allow_ips:
                    secure_scheme_headers = cfg.secure_scheme_headers
            elif isinstance(remote_addr, string_types):
                secure_scheme_headers = cfg.secure_scheme_headers

        # Parse headers into key/value pairs paying attention

bits = [bytes_to_str(bit) for bit in line_bytes.split(None, 2)]
        if len(bits) != 3:
            raise InvalidRequestLine(bytes_to_str(line_bytes))

        # Method
        if not METH_RE.match(bits[0]):
            raise InvalidRequestMethod(bits[0])
        self.method = bits[0].upper()

        # URI
        self.uri = bits[1]

        try:
            parts = split_request_uri(self.uri)
        except ValueError:
            raise InvalidRequestLine(bytes_to_str(line_bytes))
        self.path = parts.path or ""
        self.query = parts.query or ""
        self.fragment = parts.fragment or ""

        # Version
        match = VERSION_RE.match(bits[2])
        if match is None:
            raise InvalidHTTPVersion(bits[2])
        self.version = (int(match.group(1)), int(match.group(2)))

    @property
    def env(self):
        raw_env = self.settings['raw_env'].get()
        env = {}

        if not raw_env:
            return env

        for e in raw_env:
            s = _compat.bytes_to_str(e)
            try:
                k, v = s.split('=', 1)
            except ValueError:
                raise RuntimeError("environment setting %r invalid" % s)

            env[k] = v

        return env

def parse_headers(self, data):
        cfg = self.cfg
        headers = []

        # Split lines on \r\n keeping the \r\n on each line
        lines = [bytes_to_str(line) + "\r\n" for line in data.split(b"\r\n")]

        # handle scheme headers
        scheme_header = False
        secure_scheme_headers = {}
        if '*' in cfg.forwarded_allow_ips:
            secure_scheme_headers = cfg.secure_scheme_headers
        elif isinstance(self.unreader, SocketUnreader):
            remote_addr = self.unreader.sock.getpeername()
            if isinstance(remote_addr, tuple):
                remote_host = remote_addr[0]
                if remote_host in cfg.forwarded_allow_ips:
                    secure_scheme_headers = cfg.secure_scheme_headers
            elif isinstance(remote_addr, string_types):
                secure_scheme_headers = cfg.secure_scheme_headers

        # Parse headers into key/value pairs paying attention

def parse_request_line(self, line_bytes):
        bits = [bytes_to_str(bit) for bit in line_bytes.split(None, 2)]
        if len(bits) != 3:
            raise InvalidRequestLine(bytes_to_str(line_bytes))

        # Method
        if not METH_RE.match(bits[0]):
            raise InvalidRequestMethod(bits[0])
        self.method = bits[0].upper()

        # URI
        self.uri = bits[1]

        try:
            parts = split_request_uri(self.uri)
        except ValueError:
            raise InvalidRequestLine(bytes_to_str(line_bytes))
        self.path = parts.path or ""

def parse_request_line(self, line_bytes):
        bits = [bytes_to_str(bit) for bit in line_bytes.split(None, 2)]
        if len(bits) != 3:
            raise InvalidRequestLine(bytes_to_str(line_bytes))

        # Method
        if not METH_RE.match(bits[0]):
            raise InvalidRequestMethod(bits[0])
        self.method = bits[0].upper()

        # URI
        self.uri = bits[1]

        try:
            parts = split_request_uri(self.uri)
        except ValueError:
            raise InvalidRequestLine(bytes_to_str(line_bytes))
        self.path = parts.path or ""

bits = [bytes_to_str(bit) for bit in line_bytes.split(None, 2)]
        if len(bits) != 3:
            raise InvalidRequestLine(bytes_to_str(line_bytes))

        # Method
        if not METH_RE.match(bits[0]):
            raise InvalidRequestMethod(bits[0])
        self.method = bits[0].upper()

        # URI
        self.uri = bits[1]

        try:
            parts = split_request_uri(self.uri)
        except ValueError:
            raise InvalidRequestLine(bytes_to_str(line_bytes))
        self.path = parts.path or ""
        self.query = parts.query or ""
        self.fragment = parts.fragment or ""

        # Version
        match = VERSION_RE.match(bits[2])
        if match is None:
            raise InvalidHTTPVersion(bits[2])
        self.version = (int(match.group(1)), int(match.group(2)))

def address(self):
        s = self.settings['bind'].get()
        return [util.parse_address(_compat.bytes_to_str(bind)) for bind in s]

def parse(self, unreader):
        buf = BytesIO()
        self.get_data(unreader, buf, stop=True)

        # get request line
        line, rbuf = self.read_line(unreader, buf, self.limit_request_line)

        # proxy protocol
        if self.proxy_protocol(bytes_to_str(line)):
            # get next request line
            buf = BytesIO()
            buf.write(rbuf)
            line, rbuf = self.read_line(unreader, buf, self.limit_request_line)

        self.parse_request_line(line)
        buf = BytesIO()
        buf.write(rbuf)

        # Headers
        data = buf.getvalue()
        idx = data.find(b"\r\n\r\n")

        done = data[:2] == b"\r\n"
        while True:
            idx = data.find(b"\r\n\r\n")

def parse(self, unreader):
        buf = BytesIO()
        self.get_data(unreader, buf, stop=True)

        # get request line
        line, rbuf = self.read_line(unreader, buf, self.limit_request_line)

        # proxy protocol
        if self.proxy_protocol(bytes_to_str(line)):
            # get next request line
            buf = BytesIO()
            buf.write(rbuf)
            line, rbuf = self.read_line(unreader, buf, self.limit_request_line)

        self.parse_request_line(line)
        buf = BytesIO()
        buf.write(rbuf)

        # Headers
        data = buf.getvalue()
        idx = data.find(b"\r\n\r\n")

        done = data[:2] == b"\r\n"
        while True:
            idx = data.find(b"\r\n\r\n")