old_contents: # -*- coding: utf-8 -*-
  
  
  class SchemaDriver(object):
      @staticmethod
      def migrate(dsn, table, fields, indexes, foreign_keys):
          raise NotImplementedError
  
      @staticmethod
      def migrate_data(dsn, table):
          raise NotImplementedError
  
      @staticmethod
      def migrate_fields(proxy, table, fields, exist):
          raise NotImplementedError
  
      @staticmethod
      def _migrate_fields_create(proxy, table, fields, exist):
          raise NotImplementedError
  
      @staticmethod
      def migrate_indexes(proxy, table, indexes, exist):
          raise NotImplementedError
  
      @staticmethod
      def migrate_foreign_keys(proxy, table, foreign_keys, exist):
          raise NotImplementedError
  
new_contents: # -*- coding: utf-8 -*-
  
  
  class SchemaDriver(object):
      @staticmethod
      def migrate(dsn, table, fields, indexes, foreign_keys):
          raise NotImplementedError
  
      @staticmethod
      def migrate_data(dsn, table):
          raise NotImplementedError
  
subject: remove unnecessary interface methods.