text: #ifndef DATA_SCIENCE_UTIL_H
  #define DATA_SCIENCE_UTIL_H
  
  #include <iostream>
  #include <vector>
  
  
  namespace util{
      bool str_contains_lower(std::string str1, std::string str2);
      std::string str_tolower(std::string str);
      void save_results(std::vector<std::string> data);
  }
  
  #endif
  