A draft of a message in the topic; may be null if none.
Basic information about the topic.
Optional is_True, if the topic is pinned in the topic list.
Last message in the topic; may be null if unknown.
Identifier of the last read incoming message.
Identifier of the last read outgoing message.
Notification settings for the topic.
Number of unread messages in the topic.
Number of unread messages with a mention/reply in the topic.
Number of messages with unread reactions in the topic.
Describes a forum topic.