code: def test_duplicate_index():
      X = X_cat.copy()
      X.index = np.ones(len(X), np.int64)
      assert not X.index.is_unique
      with pytest.raises(ValueError):
          detect_types(X)
      with pytest.warns(UserWarning):
          X_clean = clean(X)
      assert X_clean.index.is_unique
  
imports: import os
  import pytest
  import random
  import string
  import warnings
  import numpy
  import pandas
  from sklearn.datasets import load_iris, load_digits
  from sklearn.model_selection import train_test_split
  from sklearn.pipeline import make_pipeline
  from sklearn.linear_model import LogisticRegression
  from dabl.preprocessing import USELESS_TYPES, detect_types, EasyPreprocessor, DirtyFloatCleaner, clean, _FLOAT_REGEX, _float_matching, detect_type_series
  from dabl.utils import data_df_from_bunch
  from dabl.datasets import load_titanic
  from dabl import plot
label_desc: Use image node_id 4 for calling a global function with example usage: test_duplicate_index() without return types