protected Text transformToUTF8(Writable blob) {
    Text text = (Text) blob;
    return SerDeUtils.transformTextToUTF8(text, this.charset);
  }
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