code: def schema(self):
          
          if not self.__schema:
              # Inherit context from parent.
              context = getattr(self.parent, 'context', {})
              if isinstance(self.nested, SchemaABC):
                  self.__schema = self.nested
                  self.__schema.context.update(context)
              else:
                  if isinstance(self.nested, type) and issubclass(self.nested, SchemaABC):
                      schema_class = self.nested
                  elif not isinstance(self.nested, basestring):
                      raise ValueError(
                          'Nested fields must be passed a '
                          'Schema, not {}.'.format(self.nested.__class__),
                      )
                  elif self.nested == 'self':
                      schema_class = self.parent.__class__
                  else:
                      schema_class = class_registry.get_class(self.nested)
                  self.__schema = schema_class(
                      many=self.many,
                      only=self.only,
                      exclude=self.exclude,
                      context=context,
                      load_only=self._nested_normalized_option('load_only'),
                      dump_only=self._nested_normalized_option('dump_only'),
                  )
          return self.__schema
docs: The nested Schema object.
  
          .. versionchanged:: 1.0.0
              Renamed from `serializer` to `schema`