new_contents: # -*- coding: utf-8 -*-
  from __future__ import absolute_import
  
  from .schema import (
      TableSchemaOpts,
      ModelSchemaOpts,
      TableSchema,
      ModelSchema,
  )
  
  from .convert import (
      ModelConverter,
      fields_for_model,
      property2field,
      column2field,
      field_for,
  )
  from .exceptions import ModelConversionError
  
  
  __all__ = [
      'TableSchema',
      'ModelSchema',
      'TableSchemaOpts',
      'ModelSchemaOpts',
      'ModelConverter',
      'fields_for_model',
      'property2field',
      'column2field',
      'ModelConversionError',
      'field_for',
  ]
  
subject: Update app/helpers/marshmallow/__init__.py