@Explain(vectorization = Vectorization.DETAIL, displayName = "includeColumns",
          explainLevels = { Level.DEFAULT, Level.EXTENDED })
      public String getDataColumnNums() {
        int[] dataColumnNums = vectorizedRowBatchCtx.getDataColumnNums();
        if (dataColumnNums == null) {
          return null;
        }
        return Arrays.toString(dataColumnNums);
      }
Returns a set containing all leaf operators from the operator tree in this work.
@return a set containing all leaf operators in this operator tree.
ql/src/java/org/apache/hadoop/hive/ql/plan/BaseWork.java