code: def rebalance_leaders(self):
          
          opt_leader_cnt = len(self.cluster_topology.partitions) // len(self.cluster_topology.brokers)
          # Balanced brokers transfer leadership to their under-balanced followers
          self.rebalancing_non_followers(opt_leader_cnt)
docs: Re-order brokers in replicas such that, every broker is assigned as
          preferred leader evenly.