code: def test_wp_eval_basic():
      result = happy_wp.eval(
          "../data/wp/train-eval.txt", args=WPEvalArgs(max_length=512)
      )
      assert type(result.loss) == float
  
imports: from pytest import approx
  from happytransformer import HappyWordPrediction, WPTrainArgs, WPEvalArgs
  from happytransformer.happy_word_prediction import WordPredictionResult
  from tests.run_save_load import run_save_load
  import pytest
  from tests import happy_wp
label_desc: Use image node_id 7 for calling a global function with example usage: test_wp_eval_basic() without return types