message: Update docstring to clarify exception
diff: @@ -496,7 +496,7 @@ def convert_entity_to_ast(o, program_ctx):
  keyed by their symbol name.
  Raises:
  - NotImplementedError: if the object conversion is not yet supported.
  + NotImplementedError: if entity is of a type that is not yet supported.
  """
  logging.log(1, 'Converting %s', o)
  