Accumulates playlist edit operations and serializes them to the diff string expected by users/{uid}/playlists/{kind}/change.
diff
users/{uid}/playlists/{kind}/change
Append a delete operation removing tracks in the half-open range [from, to).
[from, to)
Start index (inclusive).
End index (exclusive).
This builder, for chaining.
Append an insert operation placing tracks at the given index.
Insertion index.
A single track reference or a list of them.
Serialize the accumulated operations to a JSON string.
Accumulates playlist edit operations and serializes them to the
diffstring expected byusers/{uid}/playlists/{kind}/change.