text: #ifndef QUACK_HPP
  #define QUACK_HPP
  
  #include "QuackBehavior.hpp"
  
  #include <iostream>
  
  class Quack : public QuackBehavior
  {
  public:
      void quack()
      {
          std::cout << "Quack" << std::endl;
      }
  };
  
  #endif