old_contents: # -*- coding: utf-8 -*-
  """Exception classes for marshmallow-related errors."""
  
  from marshmallow.compat import basestring
  
  
  # Key used for schema-level validation errors
  SCHEMA = '_schema'
  
  
  class MarshmallowError(Exception):
      """Base class for all marshmallow-related errors."""
  
  
  class ValidationError(MarshmallowError):
      """Raised when validation fails on a field or schema.
  
      Validators and custom fields should raise this exception.
  
      :param str|list|dict message: An error message, list of error messages, or dict of
          error messages. If a dict, the keys are subitems and the values are error messages.
      :param str field_name: Field name to store the error on.
          If `None`, the error is stored as schema-level error.
      :param list fields: `Field` objects to which the error applies.
      :param dict data: Raw input data.
      :param dict valid_data: Valid (de)serialized data.
      """
      def __init__(self, message, field_name=SCHEMA, data=None, valid_data=None, **kwargs):
          self.messages = [message] if isinstance(message, basestring) else message
          self.field_name = field_name
          self.data = data
          self.valid_data = valid_data
          self.kwargs = kwargs
          MarshmallowError.__init__(self, message)
  
      def normalized_messages(self):
          if self.field_name == SCHEMA and isinstance(self.messages, dict):
              return self.messages
          return {self.field_name: self.messages}
  
  
  class RegistryError(NameError):
      """Raised when an invalid operation is performed on the serializer
      class registry.
      """
  
  
  class StringNotCollectionError(MarshmallowError, TypeError):
      """Raised when a string is passed when a list of strings is expected."""
  
  
  class FieldInstanceResolutionError(MarshmallowError, TypeError):
      """Raised when schema to instantiate is neither a Schema class nor an instance."""
  
new_contents: # -*- coding: utf-8 -*-
  """Exception classes for marshmallow-related errors."""
  
  from marshmallow.compat import basestring
  
  
  # Key used for schema-level validation errors
  SCHEMA = '_schema'
  
  
  class MarshmallowError(Exception):
      """Base class for all marshmallow-related errors."""
  
  
  class ValidationError(MarshmallowError):
      """Raised when validation fails on a field or schema.
  
      Validators and custom fields should raise this exception.
  
      :param str|list|dict message: An error message, list of error messages, or dict of
          error messages. If a dict, the keys are subitems and the values are error messages.
      :param str field_name: Field name to store the error on.
          If `None`, the error is stored as schema-level error.
      :param dict data: Raw input data.
      :param dict valid_data: Valid (de)serialized data.
      """
      def __init__(self, message, field_name=SCHEMA, data=None, valid_data=None, **kwargs):
          self.messages = [message] if isinstance(message, basestring) else message
          self.field_name = field_name
          self.data = data
          self.valid_data = valid_data
          self.kwargs = kwargs
          MarshmallowError.__init__(self, message)
  
      def normalized_messages(self):
          if self.field_name == SCHEMA and isinstance(self.messages, dict):
              return self.messages
          return {self.field_name: self.messages}
  
  
  class RegistryError(NameError):
      """Raised when an invalid operation is performed on the serializer
      class registry.
      """
  
  
  class StringNotCollectionError(MarshmallowError, TypeError):
      """Raised when a string is passed when a list of strings is expected."""
  
  
  class FieldInstanceResolutionError(MarshmallowError, TypeError):
      """Raised when schema to instantiate is neither a Schema class nor an instance."""
  
subject: Remove the deprecated fields param from ValidationError