text: #ifndef FRAGMENT_SORT_H_
  #define FRAGMENT_SORT_H_
  
  
  template<typename T_Fragment>
  class LexicographicFragmentSort {
   public:
  	int operator()(const T_Fragment &a, const T_Fragment &b) const {
  		return a.LessThanXY(b);
  	}
  };
  
  
  template<typename T_Fragment>
  class LexicographicFragmentSortByY {
   public:
  	int operator()(const T_Fragment &a, const T_Fragment &b) const {
  		return a.LessThanYX(b);
  	}
  };
  
  
  
  
  #endif
  