code: def test_passing_source_features_without_proper_configuration(self):
      model_id = 0
      opt = {"models": ["test_model.pt"]}
      model_root = TEST_DIR
      sm = ServerModel(opt, model_id, model_root=model_root, load=True)
      with self.assertRaises(AssertionError):
          sm.maybe_preprocess({"src": "hello￨0 world￨1"})
      sm = ServerModel(
          opt,
          model_id,
          model_root=model_root,
          load=True,
          features_opt={
              "n_src_feats": 2,
              "src_feats_defaults": "0￨0",
              "reversible_tokenization": "joiner",
          },
      )
      with self.assertRaises(AssertionError):
          sm.maybe_preprocess({"src": "hello￨0 world￨1"})
  
imports: import unittest
  from onmt.translate.translation_server import ServerModel, TranslationServer
  import os
  from textwrap import dedent
  import torch
  from onmt.translate.translator import Translator
label_desc: Use image node_id 6 for calling the TestServerModel obj's underlying member method code with example usage: obj.test_passing_source_features_without_proper_configuration() without return types