_steamGuardPrompt(domain, lastCodeWrong, callback) {
		if (this.listenerCount('steamGuard') == 0) {
			// No steamGuard listeners, so prompt for one from stdin

			let rl = require('readline').createInterface({
				input: process.stdin,
				output: process.stdout
			});

			rl.question('Steam Guard' + (!domain ? ' App' : '') + ' Code: ', function(code) {
				rl.close();
				callback(code);
			});
		} else {
			this.emit('steamGuard', domain, callback, lastCodeWrong);
		}
	}
@param {string} domain
@param {boolean} lastCodeWrong
@param {function} callback
@private