How to use the future.builtins.bytes function in future

def unquote_to_bytes(string):
    """unquote_to_bytes('abc%20def') -> b'abc def'."""
    # Note: strings are encoded as UTF-8. This is only an issue if it contains
    # unescaped non-ASCII characters, which URIs should not.
    if not string:
        # Is it a string-like object?
        string.split
        return bytes(b'')
    if isinstance(string, str):
        string = string.encode('utf-8')
    ### For Python-Future:
    # It is already a byte-string object, but force it to be newbytes here on
    # Py2:
    string = bytes(string)
    ###
    bits = string.split(b'%')
    if len(bits) == 1:
        return string
    res = [bits[0]]
    append = res.append
    for item in bits[1:]:
        try:
            append(_hextobyte[item[:2]])
            append(item[2:])

def unquote_to_bytes(string):
    """unquote_to_bytes('abc%20def') -> b'abc def'."""
    # Note: strings are encoded as UTF-8. This is only an issue if it contains
    # unescaped non-ASCII characters, which URIs should not.
    if not string:
        # Is it a string-like object?
        string.split
        return bytes(b'')
    if isinstance(string, str):
        string = string.encode('utf-8')
    ### For Python-Future:
    # It is already a byte-string object, but force it to be newbytes here on
    # Py2:
    string = bytes(string)
    ###
    bits = string.split(b'%')
    if len(bits) == 1:
        return string
    res = [bits[0]]
    append = res.append
    for item in bits[1:]:
        try:
            append(_hextobyte[item[:2]])
            append(item[2:])
        except KeyError:
            append(b'%')
            append(item)
    return bytes(b'').join(res)

sockaddr = ctypes.cast(ifaddr.ifa_addr, ctypes.POINTER(Sockaddr))
    iffamily = sockaddr.contents.sa_family
    if iffamily == AF_INET:
      sockaddrin = ctypes.cast(ifaddr.ifa_addr, ctypes.POINTER(Sockaddrin))

      address = rdf_client_network.NetworkAddress()
      address.address_type = rdf_client_network.NetworkAddress.Family.INET
      address.packed_bytes = struct.pack("=L", sockaddrin.contents.sin_addr)
      iface.addresses.append(address)
    elif iffamily == AF_INET6:
      sockaddrin = ctypes.cast(ifaddr.ifa_addr, ctypes.POINTER(Sockaddrin6))

      address = rdf_client_network.NetworkAddress()
      address.address_type = rdf_client_network.NetworkAddress.Family.INET6
      address.packed_bytes = bytes(list(sockaddrin.contents.sin6_addr))
      iface.addresses.append(address)
    elif iffamily == AF_LINK:
      sockaddrdl = ctypes.cast(ifaddr.ifa_addr, ctypes.POINTER(Sockaddrdl))

      nlen = sockaddrdl.contents.sdl_nlen
      alen = sockaddrdl.contents.sdl_alen
      iface.mac_address = bytes(sockaddrdl.contents.sdl_data[nlen:nlen + alen])
    else:
      raise ValueError("Unexpected socket address family: %s" % iffamily)

  return itervalues(ifaces)

def _tunnel(self):
        self._set_hostport(self._tunnel_host, self._tunnel_port)
        connect_str = "CONNECT %s:%d HTTP/1.0\r\n" % (self.host, self.port)
        connect_bytes = connect_str.encode("ascii")
        self.send(connect_bytes)
        for header, value in self._tunnel_headers.items():
            header_str = "%s: %s\r\n" % (header, value)
            header_bytes = header_str.encode("latin-1")
            self.send(header_bytes)
        self.send(bytes(b'\r\n'))

        response = self.response_class(self.sock, method=self._method)
        (version, code, message) = response._read_status()

        if code != 200:
            self.close()
            raise socket.error("Tunnel connection failed: %d %s" % (code,
                                                                    message.strip()))
        while True:
            line = response.fp.readline(_MAXLINE + 1)
            if len(line) > _MAXLINE:
                raise LineTooLong("header line")
            if not line:
                # for sites which EOF without sending a trailer
                break
            if line in (b'\r\n', b'\n', b''):

def _send_output(self, message_body=None):
        """Send the currently buffered request and clear the buffer.

        Appends an extra \\r\\n to the buffer.
        A message_body may be specified, to be appended to the request.
        """
        self._buffer.extend((bytes(b""), bytes(b"")))
        msg = bytes(b"\r\n").join(self._buffer)
        del self._buffer[:]
        # If msg and message_body are sent in a single send() call,
        # it will avoid performance problems caused by the interaction
        # between delayed ack and the Nagle algorithm.
        if isinstance(message_body, bytes):
            msg += message_body
            message_body = None
        self.send(msg)
        if message_body is not None:
            # message_body was not a string (i.e. it is a file), and
            # we must run the risk of Nagle.
            self.send(message_body)

def read(self, amt=None):
        if self.fp is None:
            return bytes(b"")

        if self._method == "HEAD":
            self._close_conn()
            return bytes(b"")

        if amt is not None:
            # Amount is given, so call base class version
            # (which is implemented in terms of self.readinto)
            return bytes(super(HTTPResponse, self).read(amt))
        else:
            # Amount is not given (unbounded read) so we must check self.length
            # and self.chunked

            if self.chunked:
                return self._readall_chunked()

            if self.length is None:
                s = self.fp.read()
            else:
                try:
                    s = self._safe_read(self.length)
                except IncompleteRead:
                    self._close_conn()
                    raise
                self.length = 0

value = nv[1].replace('+', ' ')
            value = unquote(value, encoding=encoding, errors=errors)
            value = _coerce_result(value)
            r.append((name, value))
    return r

def unquote_plus(string, encoding='utf-8', errors='replace'):
    """Like unquote(), but also replace plus signs by spaces, as required for
    unquoting HTML form values.

    unquote_plus('%7e/abc+def') -> '~/abc def'
    """
    string = string.replace('+', ' ')
    return unquote(string, encoding, errors)

_ALWAYS_SAFE = frozenset(bytes(b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                               b'abcdefghijklmnopqrstuvwxyz'
                               b'0123456789'
                               b'_.-'))
_ALWAYS_SAFE_BYTES = bytes(_ALWAYS_SAFE)
_safe_quoters = {}

class Quoter(collections.defaultdict):
    """A mapping from bytes (in range(0,256)) to strings.

    String values are percent-encoded byte values, unless the key < 128, and
    in the "safe" set (either the specified safe set, or default set).
    """
    # Keeps a cache internally, using defaultdict, for efficiency (lookups
    # of cached keys don't call Python code at all).
    def __init__(self, safe):
        """safe: bytes object."""

"""Send a request header line to the server.

        For example: h.putheader('Accept', 'text/html')
        """
        if self.__state != _CS_REQ_STARTED:
            raise CannotSendHeader()

        if hasattr(header, 'encode'):
            header = header.encode('ascii')
        values = list(values)
        for i, one_value in enumerate(values):
            if hasattr(one_value, 'encode'):
                values[i] = one_value.encode('latin-1')
            elif isinstance(one_value, int):
                values[i] = str(one_value).encode('ascii')
        value = bytes(b'\r\n\t').join(values)
        header = header + bytes(b': ') + value
        self._output(header)

def __init__(self, safe):
        """safe: bytes object."""
        self.safe = _ALWAYS_SAFE.union(bytes(safe))