code: def test_detect_types_empty():
      X = pd.DataFrame(index=range(100))
      types = detect_types(X)
      assert (types == bool).all(axis=None)
  
      known_types = [
          "continuous",
          "dirty_float",
          "low_card_int_ordinal",
          "low_card_int_categorical",
          "categorical",
          "date",
          "free_string",
          "useless",
      ]
      assert (types.columns == known_types).all()
  
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 14 for calling a global function with example usage: test_detect_types_empty() without return types