title: .NET Core Custom model binder call default model binder
body: <p>I'm trying to implement some middleware in .NET Core that rounds decimals to 2 decimal places. All of the other mapping can work as it currently does via the <code>ComplexTypeModelBinder</code>. I've tried calling that binder before mine or inheriting from it, but it ends up with the model just being null when it hits the controller.</p>
  
  <p>Essentially I'm after the same functionality as asked here: <a href="https://stackoverflow.com/questions/6411993/call-default-model-binder-from-a-custom-model-binder">Call Default Model Binder from a Custom Model Binder?</a>, but for .NET core.</p>