public function format($format = null)
    {
        if (null === $format) {
            $format = $this->_format;
        }

        return parent::format($format);
    }
public function format($format = null)
    {
        if (null === $format) {
            $format = $this->_format;
        }

        return parent::format($format);
    }
Returns date formatted according to given format.

If `$format` is `null`, it'll use `Benri_Util_DateTime::$_format`.

@param string $format Format accepted by
[date()](https://php.net/manual/en/function.date.php#refsect1-function.date-parameters)
@return string
@see Benri_Util_DateTime::setFormat() Benri_Util_DateTime::setFormat()