old_contents: # -*- coding:utf8 -*-
  """Tweet operate classes.
  """
  import datetime
  
  
  def _strptime(date_string):
      """wrapper to parse datetime-string for Twitter-API
      """
      return datetime.datetime.strptime(
          date_string,
          '%a %b %d %H:%M:%S %z %Y'
      )
  
  
  class _ConvertPattern(object):
      class ConvertFailed(Exception):
          pass
  
      class RequiredNotFound(Exception):
          pass
  
      def __init__(self, target, origin, converter=None, required=True):
          self.target = target
          self.origin = origin
          self.converter = converter
          self.required = required
  
      def junction(self, target_obj, base_dict):
          if self.origin in base_dict:
              try:
                  if self.converter:
                      attr_value_ = self.converter(base_dict[self.origin])
                  else:
                      attr_value_ = base_dict[self.origin]
                  setattr(target_obj, self.target, attr_value_)
              except:
                  raise self.ConvertFailed()
          elif self.required:
              raise self.RequiredNotFound()
  
  
  class Tweet(object):
      """Tweet object based from twitter-api json
      """
      __slot__ = ['id', 'created_at', 'text', ]
  
      CONVERT_PATTERNS = (
          _ConvertPattern('id', 'id_str'),
          _ConvertPattern('created_at', 'created_at', _strptime),
          _ConvertPattern('text', 'text'),
      )
      """convert patterns"""
  
      def __init__(self, json):
          for pattern in self.CONVERT_PATTERNS:
              pattern.junction(self, json)
  
new_contents: # -*- coding:utf8 -*-
  """Tweet operate classes.
  """
  import datetime
  
  
  def _strptime(date_string):
      """wrapper to parse datetime-string for Twitter-API
      """
      return datetime.datetime.strptime(
          date_string,
          '%a %b %d %H:%M:%S %z %Y'
      )
  
  
  class _ConvertPattern(object):
      class ConvertFailed(Exception):
          pass
  
      class RequiredNotFound(Exception):
          pass
  
      def __init__(self, target, origin, converter=None, required=True):
          self.target = target
          self.origin = origin
          self.converter = converter
          self.required = required
  
      def junction(self, target_obj, base_dict):
          if self.origin in base_dict:
              try:
                  if self.converter:
                      attr_value_ = self.converter(base_dict[self.origin])
                  else:
                      attr_value_ = base_dict[self.origin]
                  setattr(target_obj, self.target, attr_value_)
              except:
                  raise self.ConvertFailed()
          elif self.required:
              raise self.RequiredNotFound()
  
  
  class Tweet(object):
      """Tweet object based from twitter-api json
      """
      __slots__ = ['id', 'created_at', 'text', ]
  
      CONVERT_PATTERNS = (
          _ConvertPattern('id', 'id_str'),
          _ConvertPattern('created_at', 'created_at', _strptime),
          _ConvertPattern('text', 'text'),
      )
      """convert patterns"""
  
      def __init__(self, json):
          for pattern in self.CONVERT_PATTERNS:
              pattern.junction(self, json)
  
subject: modify __slot__ -> __slots__