How to use the taskcluster.exceptions.TaskclusterFailure function in taskcluster

},
                method='GET',
                ext=utils.toStr(self.makeHawkExt()),
                url=requestUrl,
                timestamp=expiration,
                nonce='',
                # content='',
                # content_type='',
            )
            bewit = mohawk.bewit.get_bewit(resource)
            return bewit.rstrip('=')

        bewit = genBewit()

        if not bewit:
            raise exceptions.TaskclusterFailure('Did not receive a bewit')

        u = urllib.parse.urlparse(requestUrl)

        qs = u.query
        if qs:
            qs += '&'
        qs += 'bewit=%s' % bewit

        return urllib.parse.urlunparse((
            u.scheme,
            u.netloc,
            u.path,
            u.params,
            qs,
            u.fragment,
        ))

paginationLimit = kwargs.get('paginationLimit', None)
                log.debug('Using method(payload=payload, query=query, params={k1: v1, k2: v2}) calling convention')

        if 'input' in entry and isinstance(payload, type(None)):
            raise exceptions.TaskclusterFailure('Payload is required')

        # These all need to be rendered down to a string, let's just check that
        # they are up front and fail fast
        for arg in args:
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'Positional arg "%s" to %s is not a string or int' % (arg, entry['name']))

        for name, arg in six.iteritems(kwApiArgs):
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'KW arg "%s: %s" to %s is not a string or int' % (name, arg, entry['name']))

        if len(args) > 0 and len(kwApiArgs) > 0:
            raise exceptions.TaskclusterFailure('Specify either positional or key word arguments')

        # We know for sure that if we don't give enough arguments that the call
        # should fail.  We don't yet know if we should fail because of two many
        # arguments because we might be overwriting positional ones with kw ones
        if len(reqArgs) > len(args) + len(kwApiArgs):
            raise exceptions.TaskclusterFailure(
                '%s takes %d args, only %d were given' % (
                    entry['name'], len(reqArgs), len(args) + len(kwApiArgs)))

        # We also need to error out when we have more positional args than required
        # because we'll need to go through the lists of provided and required args
        # at the same time.  Not disqualifying early means we'll get IndexErrors if

Bug 1284236 - Not all Taskcluster builds report correctly to the Index.
        To ensure we get a TC build force to Linux64 debug for now.

        :param properties: Properties of the build and necessary resources.
        """
        build_index = 'gecko.v2.{branch}.revision.{rev}.firefox.{platform}-debug'.format(
            branch=properties['branch'],
            rev=properties['revision'],
            platform=properties['platform'],
        )

        try:
            logger.debug('Querying Taskcluster for "desktop-test" docker image for "{}"...'.format(
                properties['branch']))
            build_task_id = taskcluster.Index().findTask(build_index)['taskId']
        except taskcluster.exceptions.TaskclusterFailure:
            raise errors.NotFoundException('Required build not found for TC index', build_index)

        task_id = None
        continuation_token = None
        while not task_id:
            options = {'limit': 5}
            if continuation_token:
                options.update({'continuationToken': continuation_token})

            resp = taskcluster.Queue().listDependentTasks(build_task_id,
                                                          options=options)
            for task in resp['tasks']:
                if task['task'].get('extra', {}).get('suite', {}).get('name') == 'firefox-ui':
                    task_id = task['status']['taskId']
                    break

auth service.

    clientId: the issuing clientId
    accessToken: the issuer's accessToken
    start: start time of credentials (datetime.datetime)
    expiry: expiration time of credentials, (datetime.datetime)
    scopes: list of scopes granted
    name: credential name (optional)

    Returns a dictionary in the form:
        { 'clientId': str, 'accessToken: str, 'certificate': str}
    """

    for scope in scopes:
        if not isinstance(scope, six.string_types):
            raise exceptions.TaskclusterFailure('Scope must be string')

    # Credentials can only be valid for 31 days.  I hope that
    # this is validated on the server somehow...

    if expiry - start > datetime.timedelta(days=31):
        raise exceptions.TaskclusterFailure('Only 31 days allowed')

    # We multiply times by 1000 because the auth service is JS and as a result
    # uses milliseconds instead of seconds
    cert = dict(
        version=1,
        scopes=scopes,
        start=calendar.timegm(start.utctimetuple()) * 1000,
        expiry=calendar.timegm(expiry.utctimetuple()) * 1000,
        seed=utils.slugId() + utils.slugId(),
    )

raise exceptions.TaskclusterFailure('Payload is required')

        # These all need to be rendered down to a string, let's just check that
        # they are up front and fail fast
        for arg in args:
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'Positional arg "%s" to %s is not a string or int' % (arg, entry['name']))

        for name, arg in six.iteritems(kwApiArgs):
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'KW arg "%s: %s" to %s is not a string or int' % (name, arg, entry['name']))

        if len(args) > 0 and len(kwApiArgs) > 0:
            raise exceptions.TaskclusterFailure('Specify either positional or key word arguments')

        # We know for sure that if we don't give enough arguments that the call
        # should fail.  We don't yet know if we should fail because of two many
        # arguments because we might be overwriting positional ones with kw ones
        if len(reqArgs) > len(args) + len(kwApiArgs):
            raise exceptions.TaskclusterFailure(
                '%s takes %d args, only %d were given' % (
                    entry['name'], len(reqArgs), len(args) + len(kwApiArgs)))

        # We also need to error out when we have more positional args than required
        # because we'll need to go through the lists of provided and required args
        # at the same time.  Not disqualifying early means we'll get IndexErrors if
        # there are more positional arguments than required
        if len(args) > len(reqArgs):
            raise exceptions.TaskclusterFailure('%s called with too many positional args',
                                                entry['name'])

raise exceptions.TaskclusterFailure('Specify either positional or key word arguments')

        # We know for sure that if we don't give enough arguments that the call
        # should fail.  We don't yet know if we should fail because of two many
        # arguments because we might be overwriting positional ones with kw ones
        if len(reqArgs) > len(args) + len(kwApiArgs):
            raise exceptions.TaskclusterFailure(
                '%s takes %d args, only %d were given' % (
                    entry['name'], len(reqArgs), len(args) + len(kwApiArgs)))

        # We also need to error out when we have more positional args than required
        # because we'll need to go through the lists of provided and required args
        # at the same time.  Not disqualifying early means we'll get IndexErrors if
        # there are more positional arguments than required
        if len(args) > len(reqArgs):
            raise exceptions.TaskclusterFailure('%s called with too many positional args',
                                                entry['name'])

        i = 0
        for arg in args:
            log.debug('Found a positional argument: %s', arg)
            routeParams[reqArgs[i]] = arg
            i += 1

        log.debug('After processing positional arguments, we have: %s', routeParams)

        routeParams.update(kwApiArgs)

        log.debug('After keyword arguments, we have: %s', routeParams)

        if len(reqArgs) != len(routeParams):
            errMsg = '%s takes %s args, %s given' % (

kwApiArgs = kwargs
                log.debug('Using method(payload, k1=v1, k2=v2) calling convention')
                warnings.warn(
                    "The method(payload, k1=v1, k2=v2) calling convention will soon be deprecated",
                    PendingDeprecationWarning
                )
            else:
                kwApiArgs = kwargs.get('params', {})
                payload = kwargs.get('payload', None)
                query = kwargs.get('query', {})
                paginationHandler = kwargs.get('paginationHandler', None)
                paginationLimit = kwargs.get('paginationLimit', None)
                log.debug('Using method(payload=payload, query=query, params={k1: v1, k2: v2}) calling convention')

        if 'input' in entry and isinstance(payload, type(None)):
            raise exceptions.TaskclusterFailure('Payload is required')

        # These all need to be rendered down to a string, let's just check that
        # they are up front and fail fast
        for arg in args:
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'Positional arg "%s" to %s is not a string or int' % (arg, entry['name']))

        for name, arg in six.iteritems(kwApiArgs):
            if not isinstance(arg, six.string_types) and not isinstance(arg, int):
                raise exceptions.TaskclusterFailure(
                    'KW arg "%s: %s" to %s is not a string or int' % (name, arg, entry['name']))

        if len(args) > 0 and len(kwApiArgs) > 0:
            raise exceptions.TaskclusterFailure('Specify either positional or key word arguments')

log.debug('After keyword arguments, we have: %s', routeParams)

        if len(reqArgs) != len(routeParams):
            errMsg = '%s takes %s args, %s given' % (
                entry['name'],
                ','.join(reqArgs),
                routeParams.keys())
            log.error(errMsg)
            raise exceptions.TaskclusterFailure(errMsg)

        for reqArg in reqArgs:
            if reqArg not in routeParams:
                errMsg = '%s requires a "%s" argument which was not provided' % (
                    entry['name'], reqArg)
                log.error(errMsg)
                raise exceptions.TaskclusterFailure(errMsg)

        return routeParams, payload, query, paginationHandler, paginationLimit