Method from_base64

libminifi/include/utils/StringUtils.h:450–453

* Base64 decodes a string * @param base64 the Base64 encoded string * @return the decoded string */

   * @return the decoded string
   */
  inline static std::string from_base64(const std::string& base64) {
    auto data = from_base64(base64.data(), base64.length());
    return std::string(reinterpret_cast<char*>(data.data()), data.size());
  }

  /**
   * Base64 encodes bytes and writes the result to base64