Transformer encoder

combo/config/from_parameters.py

@@ -59,7 +59,7 @@ def serialize_single_value(value: Any, pass_down_parameter_names: List[str] = No
         return {k: serialize_single_value(v, pass_down_parameter_names) for k, v in value.items()}
     elif isinstance(value, int) or isinstance(value, float) or isinstance(value, str):
         return value
-    elif isinstance(value, NoneType):
+    elif value is None:
         return None
     else:
         return str(value)