MQTTnet/Frameworks/MQTTnet.UniversalWindows/MqttClientFactory.cs

using System;
using MQTTnet.Core.Client;
using MQTTnet.Implementations;

namespace MQTTnet
{
    public class MqttClientFactory : IMqttClientFactory
    {
        public IMqttClient CreateMqttClient(MqttClientOptions options)
        {
            if (options == null) throw new ArgumentNullException(nameof(options));

            return new MqttClient(new MqttCommunicationAdapterFactory());
        }
    }
}