  
      def make_debug_cursor(self, cursor):
          return util.CursorDebugWrapper(cursor, self)
  
  class BaseDatabaseFeatures(object):
      allows_group_by_pk = False
      # True if django.db.backend.utils.typecast_timestamp is used on values
      # returned from dates() calls.
      needs_datetime_string_cast = True
      empty_fetchmany_value = []
 
</s>
    def schema_editor(self):
        "Returns a new instance of this backend's SchemaEditor"
        raise NotImplementedError()


  
      def make_debug_cursor(self, cursor):
          return util.CursorDebugWrapper(cursor, self)
  
    def schema_editor(self):
        "Returns a new instance of this backend's SchemaEditor"
        raise NotImplementedError()


  class BaseDatabaseFeatures(object):
      allows_group_by_pk = False
      # True if django.db.backend.utils.typecast_timestamp is used on values
      # returned from dates() calls.
      needs_datetime_string_cast = True
      empty_fetchmany_value = []
keep keep keep add keep keep keep keep keep keep
 Very start of schema alteration port. Create/delete model and some tests.
django/db/backends/__init__.py