public function saveOldValue($value = null)
    {
        if ($value) {
            $this->oldValue = $value;
        } else {
            $this->oldValue = $this->value;
        }
    }
public function saveOldValue($value = null)
    {
        if ($value) {
            $this->oldValue = $value;
        } else {
            $this->oldValue = $this->value;
        }
    }
public function saveOldValue ( $ value = null ) { if ( $ value ) { $ this -> oldValue = $ value ; } else { $ this -> oldValue = $ this -> value ; } }
Save the old value to an internal variable

@param mixed $value
@return void
Save the old value to an internal variable