code: def compress_string_factors(string_factors):
      factors = FactorUtils.extract_factors(string_factors)
      compressed_string_factors = FactorUtils.factors_to_string(factors)
      return compressed_string_factors
  
file_path: catboost/catboost/python-package/catboost/eval/factor_utils.py
imports: from enum import Enum
label_desc: Use image node_id 3 for calling the FactorUtils obj's underlying member method code with example usage: obj.compress_string_factors(string_factors) and returns: compressed_string_factors