How to use the watchgod.AllWatcher function in watchgod

def test_modify(tmpdir):
    mktree(tmpdir, tree)

    watcher = AllWatcher(str(tmpdir))
    assert watcher.check() == set()

    sleep(0.01)
    tmpdir.join('foo/bar.txt').write('foobar')

    assert watcher.check() == {(Change.modified, str(tmpdir.join('foo/bar.txt')))}

def test_add(tmpdir):
    watcher = AllWatcher(str(tmpdir))
    changes = watcher.check()
    assert changes == set()

    sleep(0.01)
    tmpdir.join('foo.txt').write('foobar')

    changes = watcher.check()
    assert changes == {(Change.added, str(tmpdir.join('foo.txt')))}

def test_delete(tmpdir):
    mktree(tmpdir, tree)

    watcher = AllWatcher(str(tmpdir))

    sleep(0.01)
    tmpdir.join('foo/bar.txt').remove()

    assert watcher.check() == {(Change.deleted, str(tmpdir.join('foo/bar.txt')))}

def test_does_not_exist(caplog):
    AllWatcher('/foo/bar')
    assert "error walking file system: FileNotFoundError [Errno 2] No such file or directory: '/foo/bar'" in caplog.text