def _validate_schema(self, schema, field, value):
        """ {'type': ['dict', 'string'],
             'anyof': [{'validator': 'schema'},
                       {'validator': 'bulk_schema'}]} """
        if schema is None:
            return

        if isinstance(value, Sequence) and not isinstance(value, _str_type):
            self.__validate_schema_sequence(field, schema, value)
        elif isinstance(value, Mapping):
            self.__validate_schema_mapping(field, schema, value)