code: def test_set_params(self):
      model = VW()
      assert getattr(model, "l") is None
  
      model.set_params(l=0.1)
      assert getattr(model, "l") == 0.1
      assert getattr(model, "vw_") is None
  
      # confirm model params reset with new construction
      model = VW()
      assert getattr(model, "l") is None
  
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 6 for calling the TestVW obj's underlying member method code with example usage: obj.test_set_params() without return types