'Returns a string representation of the :class:`Arrow <arrow.arrow.Arrow>` object,
formatted according to a format string.
:param fmt: the format string.
Usage::
>>> arrow.utcnow().format(\'YYYY-MM-DD HH:mm:ss ZZ\')
\'2013-05-09 03:56:47 -00:00\'
>>> arrow.utcnow().format(\'X\')
\'1368071882\'
>>> arrow.utcnow().format(\'MMMM DD, YYYY\')
\'May 09, 2013\'
>>> arrow.utcnow().format()
\'2013-05-09 03:56:47 -00:00\''

def format(self, fmt='YYYY-MM-DD    HH:mm:ssZZ', locale='en_us'):

    return formatter.DateTimeFormatter(locale).format(self._datetime, fmt)
