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