code: def test_default_clf():
      cl = CleanLearning()
      check1 = cl.clf is not None and hasattr(cl.clf, "fit")
      check2 = hasattr(cl.clf, "predict") and hasattr(
          cl.clf, "predict_proba"
      )
      assert check1 and check2
  
imports: from copy import deepcopy
  import warnings
  from sklearn.linear_model import LogisticRegression
  from sklearn.base import BaseEstimator
  from sklearn.model_selection import GridSearchCV
  import scipy
  import pytest
  import numpy
  import pandas
  from cleanlab.classification import CleanLearning
  from cleanlab.benchmarking.noise_generation import generate_noise_matrix_from_trace
  from cleanlab.benchmarking.noise_generation import generate_noisy_labels
  from cleanlab.internal.latent_algebra import compute_inv_noise_matrix
  from cleanlab.count import compute_confident_joint, estimate_cv_predicted_probabilities, get_confident_thresholds
  from cleanlab.filter import find_label_issues
label_desc: Use image node_id 15 for calling a global function with example usage: test_default_clf() without return types