code: def get(self):
          
          if self.num_inst == 0:
              return (self.name, float('nan'))
          else:
              return (self.name, self.sum_metric / self.num_inst)
docs: Gets the current evaluation result.
  
          Returns
          -------
          names : list of str
             Name of the metrics.
          values : list of float
             Value of the evaluations.