old_contents: # -*- coding: utf-8 -*-
  
  """Base class for all types of entries."""
  
  
  class BaseEntry(object):
      """Base class for all types of entries."""
  
      def format(self, **options):
          raise NotImplementedError()
  
      @property
      def entry_type(self):
          raise NotImplementedError()
  
      @property
      def entry_key(self):
          raise NotImplementedError()
  
      @property
      def fields(self):
          raise NotImplementedError()
  
      def aliases(self, format):
          raise NotImplementedError()
  
      def valid(self, format):
          raise NotImplementedError()
  
      def keys(self):
          raise NotImplementedError()
  
      def values(self):
          raise NotImplementedError()
  
      def __eq__(self, other):
          raise NotImplementedError()
  
      def __ne__(self, other):
          return not self == other
  
      def __contains__(self, item):
          raise NotImplementedError()
  
      def __getitem__(self, field):
          """Return the value for the given field."""
          raise NotImplementedError()
  
      def __iter__(self):
          for field in self.fields:
              yield (field, self[field])
  
      def __len__(self):
          raise NotImplementedError()
  
      def __str__(self):
          return self.format()
  
      def __repr__(self):
          raise NotImplementedError()
  
new_contents: # -*- coding: utf-8 -*-
  
  """Base class for all types of entries."""
  
  
  class BaseEntry(object):
      """Base class for all types of entries."""
  
      def format(self, **options):
          raise NotImplementedError()
  
      @property
      def entry_type(self):
          raise NotImplementedError()
  
      @property
      def entry_key(self):
          raise NotImplementedError()
  
      @property
      def fields(self):
          raise NotImplementedError()
  
      def aliases(self, format):
          raise NotImplementedError()
  
      def valid(self, format):
          raise NotImplementedError()
  
      def keys(self):
          raise NotImplementedError()
  
      def values(self):
          raise NotImplementedError()
  
      def __eq__(self, other):
          raise NotImplementedError()
  
      def __ne__(self, other):
          return not self == other
  
      def __contains__(self, item):
          raise NotImplementedError()
  
      def __getitem__(self, field):
          """Return the value for the given field."""
          raise NotImplementedError()
  
      def __iter__(self):
          for field in self.fields:
              yield (field, self[field])
  
      def __len__(self):
          raise NotImplementedError()
  
      def __str__(self):
          return self.format()
  
      def __unicode__(self):
          return unicode(str(self))
  
      def __repr__(self):
          raise NotImplementedError()
  
subject: Implement __unicode__ for entry objects