public static Text transformTextToUTF8(Text text, Charset previousCharset) {
    return new Text(new String(text.getBytes(), 0, text.getLength(), previousCharset));
  }
Returns the union of table and partition properties,
with partition properties taking precedence.
@param tblProps
@param partProps
@return the overlayed properties
serde/src/java/org/apache/hadoop/hive/serde2/SerDeUtils.java