Unseal the TradeResult Class so that we can unit test please

Hi there

Our team is unit testing our bots now, and we are running into a problem that we can't mock out any method that is part of TradeResult class because it is sealed, but we haven't found any other class that is sealed so we don't understand the need for it.

It makes it difficult because we can't mock out any properties of the class or any methods, like PlaceStopOrder, but we kind of need that.