How to use the foolscap.ipb.InvalidHintError function in foolscap

def _try():
        hint = convert_legacy_hint(location)
        if ":" not in hint:
            raise InvalidHintError("no colon")
        hint_type = hint.split(":", 1)[0]
        plugin = connectionPlugins.get(hint_type)
        if not plugin:
            connectionInfo._describe_connection_handler(location, None)
            raise InvalidHintError("no handler registered")
        connectionInfo._describe_connection_handler(location,
                                                    describe_handler(plugin))
        _update_status("resolving hint")
        d = defer.maybeDeferred(plugin.hint_to_endpoint, hint, reactor, _update_status)
        def problem(f):
            log.err(f, "error in hint_to_endpoint", level=UNUSUAL,
                    facility="foolscap.connection", umid="Fxtg6A")
            # this hint will be ignored
            return f
        d.addErrback(problem)
        return d

def _try():
        hint = convert_legacy_hint(location)
        if ":" not in hint:
            raise InvalidHintError("no colon")
        hint_type = hint.split(":", 1)[0]
        plugin = connectionPlugins.get(hint_type)
        if not plugin:
            connectionInfo._describe_connection_handler(location, None)
            raise InvalidHintError("no handler registered")
        connectionInfo._describe_connection_handler(location,
                                                    describe_handler(plugin))
        _update_status("resolving hint")
        d = defer.maybeDeferred(plugin.hint_to_endpoint, hint, reactor, _update_status)
        def problem(f):
            log.err(f, "error in hint_to_endpoint", level=UNUSUAL,
                    facility="foolscap.connection", umid="Fxtg6A")
            # this hint will be ignored
            return f
        d.addErrback(problem)
        return d
    return defer.maybeDeferred(_try)

def hint_to_endpoint(self, hint, reactor, update_status):
        mo = HINT_RE.search(hint)
        if not mo:
            raise InvalidHintError("unrecognized hint, wanted TYPE:HOST:PORT")
        host, port = mo.group(1), int(mo.group(2))
        # note: txsockx does not expose a way to provide the reactor
        ep = SOCKS5ClientEndpoint(host, port, self._proxy_endpoint)
        return ep, host

def hint_to_endpoint(self, hint, reactor, update_status):
        # Return (endpoint, hostname), where "hostname" is what we pass to the
        # HTTP "Host:" header so a dumb HTTP server can be used to redirect us.
        mo = HINT_RE.search(hint)
        if not mo:
            raise InvalidHintError("unrecognized I2P hint")
        host, portnum = mo.group(1), int(mo.group(3)) if mo.group(3) else None
        kwargs = self._kwargs
        if not portnum and 'port' in kwargs:
            portnum = kwargs.pop('port')
        ep = SAMI2PStreamClientEndpoint.new(self._sam_endpoint, host, portnum, **kwargs)
        return ep, host

def hint_to_endpoint(self, hint, reactor, update_status):
        # Return (endpoint, hostname), where "hostname" is what we pass to the
        # HTTP "Host:" header so a dumb HTTP server can be used to redirect us.
        mo = HINT_RE.search(hint)
        if not mo:
            raise InvalidHintError("unrecognized I2P hint")
        host, portnum = mo.group(1), int(mo.group(3)) if mo.group(3) else None
        ep = SAMI2PStreamClientEndpoint.new(self._sam_endpoint, host, portnum)
        return ep, host