public void setAliasBucketBaseFileNameMapping(
      Map<String, Map<String, List<String>>> aliasBucketBaseFileNameMapping) {
    this.aliasBucketBaseFileNameMapping = aliasBucketBaseFileNameMapping;
  }
was inner class of MapreLocalWork. context for bucket mapjoin (or smb join)
ql/src/java/org/apache/hadoop/hive/ql/plan/BucketMapJoinContext.java