text: //===--- plum_tomato_sauce.cpp - --------------------------------*- C++ -*-===//
  //
  //                     Head First Design Patterns
  //
  //
  //===----------------------------------------------------------------------===//
  ///
  /// \file
  /// \brief
  ///
  //===----------------------------------------------------------------------===//
  
  //https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes
  //dir2 / foo2.h.
  #include "plum_tomato_sauce.hpp"
  //C system files.
  //C++ system files.
  #include <string>
  #include <iostream>
  //Other libraries' .h files.
  //Your project's .h files.
  
  namespace headfirst {
  
  
    std::string PlumTomatoSauce::ToString() const
    {
      std::cout << "PlumTomatoSauce::ToString" << std::endl;
      return "Tomato sauce with plum tomatoes";
    }
  } //namespace headfirst
  