code: public static Element getSelectKey(IntrospectedColumn introspectedColumn, GeneratedKey generatedKey) {
          return getSelectKey(introspectedColumn, generatedKey, null);
      }
docs: This method should return an XmlElement for the select key used to
  automatically generate keys.
  @param introspectedColumn the column related to the select key statement
  @param generatedKey       the generated key for the current table
  @return the selectKey element