OptionalblacklistTreat chats as a blacklist instead of a whitelist.
OptionalchatsOnly handle updates coming from these chats - a username, an id or an
entity. Updates that carry no peer at all (updateDcOptions,
updatePrivacy and the like) never match this filter.
OptionalfuncExtra predicate; the handler runs only when it returns a truthy value.
Filters accepted by ClientUpdates.on, mirroring the event builders.