How to use the peru.plugin function in peru

def test_curl_plugin_fetch_evil_archive(self):
        # There are several evil archives checked in under tests/resources. The
        # others are checked directly as part of test_curl_plugin.py.
        fields = {
            'url': (shared.test_resources / '.tar').as_uri(),
            'unpack': 'tar',
        }
        with self.assertRaises(plugin.PluginRuntimeError):
            self.do_plugin_test('curl', fields, {})

def setUp(self):
        self.content = {"some": "stuff", "foo/bar": "baz"}
        self.content_dir = shared.create_dir(self.content)
        self.cache_root = shared.create_dir()
        self.plugin_context = plugin.PluginContext(
            cwd='.',
            plugin_cache_root=self.cache_root,
            parallelism_semaphore=asyncio.BoundedSemaphore(
                plugin.DEFAULT_PARALLEL_FETCH_LIMIT),
            plugin_cache_locks=defaultdict(asyncio.Lock),
            tmp_root=shared.create_dir())
        plugin.debug_assert_clean_parallel_count()

def setUp(self):
        self.content = {"some": "stuff", "foo/bar": "baz"}
        self.content_dir = shared.create_dir(self.content)
        self.cache_root = shared.create_dir()
        self.plugin_context = plugin.PluginContext(
            cwd='.',
            plugin_cache_root=self.cache_root,
            parallelism_semaphore=asyncio.BoundedSemaphore(
                plugin.DEFAULT_PARALLEL_FETCH_LIMIT),
            plugin_cache_locks=defaultdict(asyncio.Lock),
            tmp_root=shared.create_dir())
        plugin.debug_assert_clean_parallel_count()

def assert_parallel(n):
    # The plugin module keep a global counter of all the jobs that run in
    # parallel, so that we can write these tests.
    if plugin.DEBUG_PARALLEL_MAX != n:
        raise AssertionError('Expected {} parallel {}. Counted {}.'.format(
            n, 'job' if n == 1 else 'jobs', plugin.DEBUG_PARALLEL_MAX))

def assert_parallel(n):
    # The plugin module keep a global counter of all the jobs that run in
    # parallel, so that we can write these tests.
    if plugin.DEBUG_PARALLEL_MAX != n:
        raise AssertionError('Expected {} parallel {}. Counted {}.'.format(
            n, 'job' if n == 1 else 'jobs', plugin.DEBUG_PARALLEL_MAX))

def test_plugin_get_reup_fields(context, type, fields):
    handle = TestDisplayHandle()
    return run_task(
        plugin.plugin_get_reup_fields(context, type, fields, handle))

def _get_parallel_fetch_limit(args):
    jobs = args.get('--jobs')
    if jobs is None:
        return plugin.DEFAULT_PARALLEL_FETCH_LIMIT
    try:
        parallel = int(jobs)
        if parallel <= 0:
            raise PrintableError('Argument to --jobs must be 1 or more.')
        return parallel
    except Exception:
        raise PrintableError('Argument to --jobs must be a number.')

def get_plugin_context(self):
        return plugin.PluginContext(
            # Plugin cwd is always the directory containing peru.yaml, even if
            # the sync_dir has been explicitly set elsewhere. That's because
            # relative paths in peru.yaml should respect the location of that
            # file.
            cwd=str(Path(self.peru_file).parent),
            plugin_cache_root=self.cache.plugins_root,
            parallelism_semaphore=self.fetch_semaphore,
            plugin_cache_locks=self.plugin_cache_locks,
            tmp_root=self._tmp_root)