code: def cast_type_to_string(*, data, feature_names: list):
      """
      Cast non-str/int column to string
  
      Args:
          data (pandas): sample data
          feature_names (list): feature names which not int or str
      """
  
      def cast_to_str(x):
          return str(x)
  
      for feature_name in feature_names:
          data[feature_name] = (
              data[feature_name].astype(dtype=object).apply(cast_to_str)
          )
  
file_path: contextual-ai/xai/data/helper.py
imports: import json
  import warnings
  from collections import Counter
  from statistics import median
  import dateutil
  import numpy
  import math
  from xai.data.constants import DATATYPE, THRESHOLD
  from xai.data.explorer import CategoricalDataAnalyzer, DataAnalyzerSuite
  from xai.data.validator import MissingValidator
label_desc: Use image node_id 3 for calling a global function with example usage: cast_type_to_string() and returns: str