code: def assertTimeZoneIsNotNone(self, dt, msg=None):
          '''Fail unless ``dt`` has a non-null ``tzinfo`` attribute.
  
          Parameters
          ----------
          dt : datetime
          msg : str
              If not provided, the :mod:`marbles.mixins` or
              :mod:`unittest` standard message will be used.
  
          Raises
          ------
          TypeError
              If ``dt`` is not a datetime object.
          '''
          if not isinstance(dt, datetime):
              raise TypeError('First argument is not a datetime object')
  
          self.assertIsNotNone(dt.tzinfo, msg=msgf assertTimeZoneIsNotNone(self, dt, msg=None):
          '''Fail unless ``dt`` has a non-null ``tzinfo`` attribute.
  
          Parameters
          ----------
          dt : datetime
          msg : str
              If not provided, the :mod:`marbles.mixins` or
              :mod:`unittest` standard message will be used.
  
          Raises
          ------
          TypeError
              If ``dt`` is not a datetime object.
          '''
          if not isinstance(dt, datetime):
              raise TypeError('First argument is not a datetime object')
  
          self.assertIsNotNone(dt.tzinfo, msg=msg)
docs: Fail unless ``dt`` has a non-null ``tzinfo`` attribute.
  
          Parameters
          ----------
          dt : datetime
          msg : str
              If not provided, the :mod:`marbles.mixins` or
              :mod:`unittest` standard message will be used.
  
          Raises
          ------
          TypeError
              If ``dt`` is not a datetime object.