@Override
  public Class<? extends Writable> getSerializedClass() {
    return Text.class;
  }
OpenCSVSerde use opencsv to deserialize CSV format.
Users can specify custom separator, quote or escape characters. And the default separator(\),
quote("), and escape characters(\) are the same as the opencsv library.
serde/src/java/org/apache/hadoop/hive/serde2/OpenCSVSerde.java