@Override public void migrateBuckets(Range<Integer> splitRange,String fromShardId,String toShardId,long timeoutMs) throws ShardManagerException {
  if (!filter.isLeaderInShard(fromShardId)) {
    return;
  }
 else {
    assignBucketOnLeader(splitRange,fromShardId,toShardId,timeoutMs);
  }
}

@ Override public void migrateBuckets ( Range < Integer > splitRange , String fromShardId , String toShardId , long timeoutMs ) throws ShardManagerException { if ( ! filter . isLeaderInShard ( fromShardId ) ) { return ; } else { assignBucketOnLeader ( splitRange , fromShardId , toShardId , timeoutMs ) ; } }
splits the bucket of fromshard , and reassign the buckets to toshard .
