question: protected void triggerPreferredLeaderElection ( ZkUtils zkUtils , List < PartitionInfo > partitionInfoList ) { scala . collection . mutable . HashSet < TopicAndPartition > scalaPartitionInfoSet = new scala . collection . mutable . HashSet < > ( ) ; for ( PartitionInfo javaPartitionInfo : partitionInfoList ) { scalaPartitionInfoSet . add ( new TopicAndPartition ( _topic , javaPartitionInfo . partition ( ) ) ) ; } PreferredReplicaLeaderElectionCommand . writePreferredReplicaElectionData ( zkUtils , scalaPartitionInfoSet ) ; }
target:  This runs the preferred replica election for all partitions.