@Explain(displayName = "new column type", explainLevels = { Level.USER, Level.DEFAULT, Level.EXTENDED })
  public String getNewColumnType() {
    return newColumnType;
  }
DDL task description for ALTER TABLE ... CHANGE COLUMN ... commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/column/change/AlterTableChangeColumnDesc.java