code: def format_datetime(self, format='medium', locale='en_US'):
          
          return format_datetime(self._dt, format=format, locale=locale)
docs: Return a date string formatted to the given pattern.
  
          .. testsetup::
  
              from delorean import Delorean
  
          .. doctest::
  
              >>> d = Delorean(datetime(2015, 1, 1, 12, 30), timezone='US/Pacific')
              >>> d.format_datetime(locale='en_US')
              u'Jan 1, 2015, 12:30:00 PM'
  
              >>> d.format_datetime(format='long', locale='de_DE')
              u'1. Januar 2015 12:30:00 -0800'
  
          :param format: one of "full", "long", "medium", "short", or a custom datetime pattern
          :param locale: a locale identifier