@MLaritz: anyone know if there's a way to find in a class that implements an interface, all the public methods that aren't part of the interface? #vs

Reflection less interface methods

var targetType = typeof(Target);
  
targetType.GetMethods()
  .Select(m => m.Name)
    .Except(targetType.GetInterfaces()
      .SelectMany(i => i.GetMethods()
        .Select(im => im.Name)))
 
//---out
//ScoreGame
//ToString
//Equals
//GetHashCode
//GetType
 
public class Target : ITargetable
    {
        public void BullsEye()
        {
        }
 
        public void ScoreGame()
        {
        }
    }