Transform the MongoDB value into a Marrow Mongo value.

def to_native(self, obj, name, value):  # pylint:disable=unused-argument
		"""Transform the MongoDB value into a Marrow Mongo value."""
		
		from marrow.mongo import Document
		from marrow.mongo.trait import Derived
		
		kind = self._kind(obj.__class__)
		
		if isinstance(value, Document):
			if __debug__ and kind and issubclass(kind, Document) and not isinstance(value, kind):
				raise ValueError("Not an instance of " + kind.__name__ + " or a sub-class: " + repr(value))
			
			return value
		
		if isinstance(kind, Field):
			return kind.transformer.native(value, (kind, obj))
		
		return (kind or Derived).from_mongo(value)