Using an emitted class with CreatePredictionEngine and Predict

Question

hey all,

For an application I'm writing, I need to use CreatePredictionEngine with two emitted classes for TSrc and TDst. Those are emitted via System.Reflection.Emit. I'm creating the prediction engine as follows :

   dynamic dynamicPredictionEngine;  
   var genericPredictionMethod = description.mlContext.Model.GetType().GetMethod("CreatePredictionEngine", new[] { typeof(ITransformer), typeof(DataViewSchema) });  
   var predictionMethod = genericPredictionMethod.MakeGenericMethod(inputObject.GetType(), outputObject.GetType());  
   dynamicPredictionEngine = predictionMethod.Invoke(mlContext.Model, new object[] { TrainedModel, PredictionPipeline });  

inputObject and outputObject being instances of my two emitted classes.

When running such a prediction engine (with var result = dynamicPredictionEngine.Predict(inputObject);), I get this Exception :

   Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: 'The best overloaded method match for 'Microsoft.ML.PredictionEngineBase<inputType>.Predict(inputObject)' has some invalid arguments'  

To debug this, I created the inputType manually, instead of using my emitted class. This works fine if input type is created manually, and output type is emitted. I checked in the debugger to see what differs between my emitted class and the manually created one, they seem to match :

inputObject is emitted, TaxiTrip is manually created.

I'm totally new to this Reflection.Emit thing, and I have no idea what could cause the Predict function to fail, since both classes seem to have the same properties here.

Does anyone have an idea?

Thanks in advance!