old_contents: # -*- coding: utf-8 -*-
  """Abstract base classes.
  
  These are necessary to avoid circular imports between core.py and fields.py.
  """
  import copy
  
  
  class FieldABC(object):
      """Abstract base class from which all Field classes inherit.
      """
      parent = None
      name = None
  
      def serialize(self, attr, obj, accessor=None):
          raise NotImplementedError
  
      def deserialize(self, value):
          raise NotImplementedError
  
      def _serialize(self, value, attr, obj, **kwargs):
          raise NotImplementedError
  
      def _deserialize(self, value, attr, data, **kwargs):
          raise NotImplementedError
  
      def __deepcopy__(self, memo):
          ret = copy.copy(self)
          return ret
  
  
  class SchemaABC(object):
      """Abstract base class from which all Schemas inherit."""
  
      def dump(self, obj):
          raise NotImplementedError
  
      def dumps(self, obj, *args, **kwargs):
          raise NotImplementedError
  
      def load(self, data):
          raise NotImplementedError
  
      def loads(self, data):
          raise NotImplementedError
  
new_contents: # -*- coding: utf-8 -*-
  """Abstract base classes.
  
  These are necessary to avoid circular imports between core.py and fields.py.
  """
  import copy
  
  
  class FieldABC(object):
      """Abstract base class from which all Field classes inherit.
      """
      parent = None
      name = None
  
      def serialize(self, attr, obj, accessor=None):
          raise NotImplementedError
  
      def deserialize(self, value):
          raise NotImplementedError
  
      def _serialize(self, value, attr, obj, **kwargs):
          raise NotImplementedError
  
      def _deserialize(self, value, attr, data, **kwargs):
          raise NotImplementedError
  
      def __deepcopy__(self, memo):
          ret = copy.copy(self)
          return ret
  
  
  class SchemaABC(object):
      """Abstract base class from which all Schemas inherit."""
  
      def dump(self, obj, many=None):
          raise NotImplementedError
  
      def dumps(self, obj, many=None, *args, **kwargs):
          raise NotImplementedError
  
      def load(self, data, many=None, partial=None, unknown=None):
          raise NotImplementedError
  
      def loads(
          self, json_data, many=None, partial=None, unknown=None,
          **kwargs
      ):
          raise NotImplementedError
  
subject: Update SchemaABC method signatures