text: #ifndef GUARD_H
  #define GUARD_H
  
  #include <string>
  
  class Property;
  
  class Guard {
      std::string name;
      Property* property;
      void alert(std::string);
      void setProperty(Property* p);
      friend class Property;
  public:
      Guard(std::string);
  };
  
  #endif
  