code: def __check_for_binary_target(y):
      """
      Helper function to check if a target column is binary.
      Checks if only the values true and false (or 0 and 1) are present in the values.
  
      :param y: the values to check for.
      :type y: pandas.Series or numpy.array
  
      :return: None
      :rtype: None
  
      :raises: ``ValueError`` if the values are not binary.
      """
      if not set(y) == {0, 1}:
          if len(set(y)) > 2:
              raise ValueError("Target is not binary!")
  
          warnings.warn(
              "The binary target should have "
              "values 1 and 0 (or True and False). "
              "Instead found" + str(set(y)),
              RuntimeWarning,
          )
  
file_path: tsfresh/tsfresh/feature_selection/significance_tests.py
imports: import warnings
  from builtins import str
  import numpy
  import pandas
  from scipy import stats
label_desc: Use image node_id 6 for calling a global function with example usage: __check_for_binary_target(y) without return types