How to use the cheroot.errors.NoSSLError function in cheroot

def _conditional_error(self, req, response):
        """Respond with an error.

        Don't bother writing if a response
        has already started being written.
        """
        if not req or req.sent_headers:
            return

        try:
            req.simple_response(response)
        except errors.FatalSSLAlert:
            pass
        except errors.NoSSLError:
            self._handle_no_ssl(req)

"""Wrap and return the given socket, plus WSGI environ entries."""
        EMPTY_RESULT = None, {}
        try:
            s = self.context.wrap_socket(
                sock, do_handshake_on_connect=True, server_side=True,
            )
        except ssl.SSLError as ex:
            if ex.errno == ssl.SSL_ERROR_EOF:
                # This is almost certainly due to the cherrypy engine
                # 'pinging' the socket to assert it's connectable;
                # the 'ping' isn't SSL.
                return EMPTY_RESULT
            elif ex.errno == ssl.SSL_ERROR_SSL:
                if _assert_ssl_exc_contains(ex, 'http request'):
                    # The client is speaking HTTP to an HTTPS server.
                    raise errors.NoSSLError

                # Check if it's one of the known errors
                # Errors that are caught by PyOpenSSL, but thrown by
                # built-in ssl
                _block_errors = (
                    'unknown protocol', 'unknown ca', 'unknown_ca',
                    'unknown error',
                    'https proxy request', 'inappropriate fallback',
                    'wrong version number',
                    'no shared cipher', 'certificate unknown',
                    'ccs received early',
                )
                if _assert_ssl_exc_contains(ex, *_block_errors):
                    # Accepted error, let's pass
                    return EMPTY_RESULT
            elif _assert_ssl_exc_contains(ex, 'handshake operation timed out'):

if is_reader and errnum in errors.socket_errors_to_ignore:
                    return ''
                raise socket.error(errnum)
            except SSL.Error as e:
                if is_reader and e.args == (-1, 'Unexpected EOF'):
                    return ''

                thirdarg = None
                try:
                    thirdarg = e.args[0][0][2]
                except IndexError:
                    pass

                if thirdarg == 'http request':
                    # The client is talking HTTP to an HTTPS server.
                    raise errors.NoSSLError()

                raise errors.FatalSSLAlert(*e.args)

            if time.time() - start > self.ssl_timeout:
                raise socket.timeout('timed out')

def _from_server_socket(self, server_socket):
        try:
            s, addr = server_socket.accept()
            if self.server.stats['Enabled']:
                self.server.stats['Accepts'] += 1
            prevent_socket_inheritance(s)
            if hasattr(s, 'settimeout'):
                s.settimeout(self.server.timeout)

            mf = MakeFile
            ssl_env = {}
            # if ssl cert and key are set, we try to be a secure HTTP server
            if self.server.ssl_adapter is not None:
                try:
                    s, ssl_env = self.server.ssl_adapter.wrap(s)
                except errors.NoSSLError:
                    msg = (
                        'The client sent a plain HTTP request, but '
                        'this server only speaks HTTPS on this port.'
                    )
                    buf = [
                        '%s 400 Bad Request\r\n' % self.server.protocol,
                        'Content-Length: %s\r\n' % len(msg),
                        'Content-Type: text/plain\r\n\r\n',
                        msg,
                    ]

                    sock_to_make = s if not six.PY2 else s._sock
                    wfile = mf(sock_to_make, 'wb', io.DEFAULT_BUFFER_SIZE)
                    try:
                        wfile.write(''.join(buf).encode('ISO-8859-1'))
                    except socket.error as ex:

if is_reader and errnum in errors.socket_errors_to_ignore:
                    return b''
                raise socket.error(errnum)
            except SSL.Error as e:
                if is_reader and e.args == (-1, 'Unexpected EOF'):
                    return b''

                thirdarg = None
                try:
                    thirdarg = e.args[0][0][2]
                except IndexError:
                    pass

                if thirdarg == 'http request':
                    # The client is talking HTTP to an HTTPS server.
                    raise errors.NoSSLError()

                raise errors.FatalSSLAlert(*e.args)

            if time.time() - start > self.ssl_timeout:
                raise socket.timeout('timed out')

"""Wrap and return the given socket, plus WSGI environ entries."""
        EMPTY_RESULT = None, {}
        try:
            s = self.context.wrap_socket(
                sock, do_handshake_on_connect=True, server_side=True,
            )
        except ssl.SSLError as ex:
            if ex.errno == ssl.SSL_ERROR_EOF:
                # This is almost certainly due to the cherrypy engine
                # 'pinging' the socket to assert it's connectable;
                # the 'ping' isn't SSL.
                return EMPTY_RESULT
            elif ex.errno == ssl.SSL_ERROR_SSL:
                if _assert_ssl_exc_contains(ex, 'http request'):
                    # The client is speaking HTTP to an HTTPS server.
                    raise errors.NoSSLError

                # Check if it's one of the known errors
                # Errors that are caught by PyOpenSSL, but thrown by
                # built-in ssl
                _block_errors = (
                    'unknown protocol', 'unknown ca', 'unknown_ca',
                    'unknown error',
                    'https proxy request', 'inappropriate fallback',
                    'wrong version number',
                    'no shared cipher', 'certificate unknown',
                    'ccs received early',
                    'certificate verify failed',  # client cert w/o trusted CA
                )
                if _assert_ssl_exc_contains(ex, *_block_errors):
                    # Accepted error, let's pass
                    return EMPTY_RESULT