async def METHOD_NAME(request, reactor, temp_filepath, alice):
    """
    Many magic-folders can be added and left in rapid succession
    See also https://github.com/LeastAuthority/magic-folder/issues/587
    """
    names = [
        "folder_{}".format(x)
        for x in range(10)
    ]
    for name in names:
        folder = temp_filepath.child(name)
        folder.makedirs()
        await alice.add(name, folder.path)
    alice_folders = await alice.list_(True)
    assert set(alice_folders.keys()) == set(names)
    # try and ensure that the folders are "doing some work" by adding
    # files to them all (sizes are in KiB)
    fake_files = (
        ('zero', 100),  # 100K
        ('one', 10000), # 10M
    )
    for fname, size in fake_files:
        for name in names:
            with temp_filepath.child(name).child(fname).open("wb") as f:
                for _ in range(size):
                    f.write(b"xxxxxxx\n" * (1024 // 8))
    # initiate a scan on them all
    scans = await DeferredList([
        alice.scan_folder(name)
        for name in names
    ])
    assert all(ok for ok, _ in scans), "at least one scan failed"
    leaves = await DeferredList([
        alice.leave(name)
        for name in names
    ])
    assert all(ok for ok, _ in leaves), "at least one leave() failed"
    alice_folders = await alice.list_(True)
    assert not alice_folders, "should be zero folders"