/**
  * constructor
  * @param string $column_name
  * @param object $argument
  * @return void
  */
 function UpdateExpressionWithoutArgument($column_name, $argument)
 {
     parent::Expression($column_name);
     $this->argument = $argument;
 }
 /**
  * constructor
  * @param string $column_name
  * @param object $argument
  * @return void
  */
 function __construct($column_name, $argument)
 {
     parent::__construct($column_name, $argument);
     $this->argument = $argument;
 }