public void AllowOnType(PropertyComparator customComparator)
 {
     _customTypePropertyComparisons.Add(customComparator);
 }
 public void Allow(object instance, PropertyComparator customComparator)
 {
     if (!_customInstancePropertyComparisons.ContainsKey(instance))
         _customInstancePropertyComparisons.Add(instance, new List<PropertyComparator>());
     _customInstancePropertyComparisons[instance].Add(customComparator);
 }