text: #ifndef DNest4_Data
  #define DNest4_Data
  
  #include <vector>
  
  class Data
  {
  	private:
  		std::vector<double> t, y;
  
  	public:
  		Data();
  		void load(const char* filename);
  
  		// Getters
  		const std::vector<double>& get_t() const { return t; }
  		const std::vector<double>& get_y() const { return y; }
  
  	// Singleton
  	private:
  		static Data instance;
  	public:
  		static Data& get_instance() { return instance; }
  };
  
  #endif
  
  