code: def dummy_data():
      """
      Returns a dataframe with known violation of support and overlap.
  
      Two binary features (X1, X2) and a treatment indicator (T), where
      P(X1 = 1, X2 = 1) = 0
      P(T | X1 = 0, X2 = 0) = 0.5, and zero otherwise
      """
  
      return pd.DataFrame(
          np.array(
              [
                  [0, 0, 1, 0],
                  [0, 0, 0, 1],
                  [0, 1, 0, 0],
                  [1, 0, 0, 0],
              ]
              * 50
          ),
          columns=["X1", "X2", "T", "Y"],
      )
  
file_path: dowhy/tests/causal_refuters/test_assess_overlap.py
imports: import numpy
  import pandas
  import pytest
  from dowhy import CausalModel
  from dowhy.causal_refuters.assess_overlap_overrule import SupportConfig
label_desc: Use image node_id 1 for calling a global function with example usage: dummy_data() and returns: pd