text: #ifndef PID_H
  #define PID_H
  
  #include <uWS/uWS.h>
  
  class PID {
  public:
    /*
    * Errors
    */
    double p_error;
    double i_error;
    double d_error;
  
    /*
    * Coefficients
    */
    double Kp;
    double Ki;
    double Kd;
  
    /*
    * Constructor
    */
    PID();
  
    /*
    * Destructor.
    */
    virtual ~PID();
  
    /*
    * Initialize PID.
    */
    void Init(double Kp, double Ki, double Kd);
  
    /*
    * Update the PID error variables given cross track error.
    */
    void UpdateError(double cte);
  
    /*
    * Calculate the total PID error.
    */
    double TotalError();
  
    /*
    * Restart the simulator
    */
    void Restart(uWS::WebSocket<uWS::SERVER> ws);
  
  };
  
  #endif /* PID_H */
  