Add a poll option

You can add a poll option to an existing poll by using pollId and optionText in the addPollOption() method.

channel.addPollOption(pollId: poll.pollId, optionText: "new Option") { poll, error in

}

Through PollHandler, the Sendbird server always notifies whether your poll option has been successfully added.

public typealias PollHandler = (_ poll: Poll?, _ error: SBError?) -> Void