text: #ifndef MODIFIED_CUCKOO_FILTER_PRINTUTIL_H_
  #define MODIFIED_CUCKOO_FILTER_PRINTUTIL_H_
  
  #include <string>
  
  namespace modifiedcuckoofilter {
  class PrintUtil {
   public:
    static std::string bytes_to_hex(const char *data, size_t len) {
      std::string hexstr = "";
      static const char hexes[] = "0123456789ABCDEF ";
  
      for (size_t i = 0; i < len; i++) {
        unsigned char c = data[i];
        hexstr.push_back(hexes[c >> 4]);
        hexstr.push_back(hexes[c & 0xf]);
        hexstr.push_back(hexes[16]);
      }
      return hexstr;
    }
  
    static std::string bytes_to_hex(const std::string &s) {
      return bytes_to_hex((const char *)s.data(), s.size());
    }
  
   private:
    PrintUtil();
  };  // class PrintUtil
  
  }  // namespace modifiedcuckoofilter
  
  #endif  // MODIFIED_CUCKOO_FILTER_PRINTUTIL_H_
  