How to use the vaping.plugin.get_instance function in vaping

def test_init(this_dir):
    config_dir = os.path.join(this_dir, 'data', 'config', 'vodka')
    vaping.daemon.Vaping(config_dir=config_dir)
    plugin.get_instance("vodka")

def test_update_and_create():
    """
    test that update() and create() are called accordingly during
    emit()
    """
    inst = plugin.get_instance(config, None)
    t = time.time()
    inst.emit({
        "type" : "test",
        "source" : "test_update_and_create",
        "ts" : t,
        "data" : [
            { "test" : 123, "a" : "row", "b" : "1" },
            { "test" : 456, "a" : "row", "b" : "2" }
        ]
    })
    assert inst.created == True
    assert inst.updated["row-1-test"] == (t, 123)
    assert inst.updated["row-2-test"] == (t, 456)

def test_whisper(tmpdir):
    """
    test whisper-db creation and update from emit
    """

    config["filename"] = str(tmpdir.mkdir("whisper").join(FILENAME_TEMPLATE))
    inst = plugin.get_instance(config, None)
    inst.start()
    i = 0
    t = int(time.time())-10

    # emit and insert 10 data points for 2 graphs at 1 second intervals
    while i < 10:
        inst.emit({
            "type" : "test",
            "source" : "test_whisper",
            "ts" : t+i,
            "data" : [
                { "test" : 123+i, "id" : 1 },
                { "test" : 456+i, "id" : 2 }
            ]
        })
        i += 1

def test_time_parser(line,result,raises):
    inst = plugin.get_instance(config_time_parser, None)
    if raises:
        with pytest.raises(ValueError) as exception_info:
            _result = inst.process_line(line, {})
        assert str(exception_info).find(raises) > -1
    else:
        _result = inst.process_line(line, {})
        if not result:
            assert _result == result
        else:
            dt = datetime.datetime.fromtimestamp(_result["ts"])
            assert dt.strftime("%Y.%m.%d %H:%M:%S") == result

def test_parse_line(line,result,raises):
    inst = plugin.get_instance(config, None)
    if raises:
        with pytest.raises(ValueError) as exception_info:
            _result = inst.parse_line(line)
        assert str(exception_info).find(raises) > -1
    else:
        _result = inst.parse_line(line)
        assert _result == result

def test_plugin_instance():
    with pytest.raises(ValueError):
        plugin.new_plugin({}, None)

    with pytest.raises(ValueError):
        plugin.get_instance('nonexistant', None)
    with pytest.raises(ValueError):
        plugin.get_instance(['unparsable'], None)

    plugin.instantiate(config['plugin'], None)
    for each in config['plugin']:
        if 'name' not in each:
            continue
        obj = plugin.get_instance(each['name'], None)
        for k,v in list(each.items()):
            assert v == obj.config[k]

    obj = plugin.get_instance(anon_config, None)
    assert obj.config == anon_config

    # copy ctor
    obj = plugin.get_instance('fancy_copy', None)
    assert 'reeb' == obj.config['str0']

def test_plugin_instance():
    with pytest.raises(ValueError):
        plugin.new_plugin({}, None)

    with pytest.raises(ValueError):
        plugin.get_instance('nonexistant', None)
    with pytest.raises(ValueError):
        plugin.get_instance(['unparsable'], None)

    plugin.instantiate(config['plugin'], None)
    for each in config['plugin']:
        if 'name' not in each:
            continue
        obj = plugin.get_instance(each['name'], None)
        for k,v in list(each.items()):
            assert v == obj.config[k]

    obj = plugin.get_instance(anon_config, None)
    assert obj.config == anon_config

    # copy ctor
    obj = plugin.get_instance('fancy_copy', None)