text: #pragma once
  
  #include <cstdint>
  #include <string>
  
  class message {
  private:
  public:
      explicit message(std::string body = {});
  
      std::uint64_t id() const {
          return id_;
      }
  
      const std::string& body() const {
          return body_;
      }
  
      std::string to_string();
  
  private:
      std::uint64_t id_{0};
      std::string body_;
  };
  