async demoteChannelAdmin(channelId, userId) {
        return await this.pupPage.evaluate(async (channelId, userId) => {
            try {
                const userWid = window.Store.WidFactory.createWid(userId);
                await window.Store.ChannelUtils.demoteNewsletterAdmin(channelId, userWid);
                return true;
            } catch (err) {
                if (err.name === 'ServerStatusCodeError') return false;
                throw err;
            }
        }, channelId, userId);
    }
Demotes a channel admin to a regular subscriber (can be used also for self-demotion)
@param {string} channelId The channel ID to demote an admin in
@param {string} userId The user ID to demote
@returns {Promise<boolean>} Returns true if the operation completed successfully, false otherwise