code: def test_nn(self):
      vw = VW(convert_to_vw=False, nn=3)
      pos = "1.0 | a b c"
      neg = "-1.0 | d e f"
      vw.fit([pos] * 10 + [neg] * 10)
      assert vw.predict(["| a b c"]) > 0
      assert vw.predict(["| d e f"]) < 0
  
imports: from collections import namedtuple
  import os
  import numpy
  from packaging import version
  import pandas
  import pytest
  from scipy.sparse import csr_matrix
  from sklearn import datasets, __version__
  from sklearn.model_selection import KFold
  from sklearn.utils.estimator_checks import check_estimator
  from vowpalwabbit.sklearn import VW, VWClassifier, VWRegressor, tovw, VWMultiClassifier, VWRegressor
label_desc: Use image node_id 14 for calling the TestVW obj's underlying member method code with example usage: obj.test_nn() without return types