code: def merge(self, other):
      
      def merge_dict(a, b):
        for k, v in six.iteritems(b):
          a[k] += v
  
      self.replays += other.replays
      self.steps += other.steps
      self.camera_move += other.camera_move
      self.select_pt += other.select_pt
      self.select_rect += other.select_rect
      self.control_group += other.control_group
      merge_dict(self.maps, other.maps)
      merge_dict(self.races, other.races)
      merge_dict(self.unit_ids, other.unit_ids)
      merge_dict(self.valid_abilities, other.valid_abilities)
      merge_dict(self.made_abilities, other.made_abilities)
      merge_dict(self.valid_actions, other.valid_actions)
      merge_dict(self.made_actions, other.made_actions)
      self.crashing_replays |= other.crashing_replays
      self.invalid_replays |= other.invalid_replays
docs: Merge another ReplayStats into this one.