code: def extend_partial(self, times, obs_times, obs_losses, config=None):
          
          return self.predict_unseen(times, config)
docs: extends a partially observed curve
  
              Parameters:
              -----------
  
              times: numpy array
                  times where to predict the loss
              obs_times: numpy array
                  times where the curve has already been observed
              obs_losses: numpy array
                  corresponding observed losses
              config: numpy array
                  numerical reperesentation of the config; None if no config
                  information is available
                  
              Returns:
              --------
              
              mean and variance prediction at input times