code: def test_NMF_zero_ratings():
      # Non-regression test for https://github.com/NicolasHug/Surprise/pull/367
      reader = Reader(rating_scale=(-10, 10))
  
      ratings_dict = {
          "itemID": [0, 0, 0, 0, 1, 1],
          "userID": [0, 1, 2, 3, 3, 4],
          "rating": [-10, 10, 0, -5, 0, 5],
      }
      df = pd.DataFrame(ratings_dict)
      data = Dataset.load_from_df(
          df[["userID", "itemID", "rating"]], reader
      )
      trainset = data.build_full_trainset()
      algo = NMF(n_factors=4, n_epochs=2)
      algo.fit(trainset)
  
imports: import pandas
  import pytest
  from surprise import Dataset, NMF, Reader
  from surprise.model_selection import cross_validate
label_desc: Use image node_id 2 for calling a global function with example usage: test_NMF_zero_ratings() without return types