title: Error CS0433 The type 'InstanceContext' exists in both 'System.ServiceModel.Duplex, Version=4.0.1.2, ' and 'System.ServiceModel, Version=4.0.0.0'
body: <p>Add wcf service with duplex communication in uwp, I need the WSDualHttpBinding class. however the UWP framework will involve the system.servicemodel.primitives. When I add the system.servicemodel, 
  Error CS0433 The type 'InstanceContext' exists in both 'System.ServiceModel.Duplex, Version=4.0.1.2, ' and 'System.ServiceModel, Version=4.0.0.0'</p>
  
  <p>What I need is to reference the ystem.ServiceModel, Version=4.0.0.0
  how to do</p>