def METHOD_NAME(unit):
    """
    Regression test for issue #1254
        https://github.com/asdf-format/asdf/issues/1256
    This ensures that tagged strings can be properly validated against ``enum`` lists.
    """
    with asdf.config_context() as conf:
        conf.add_resource_mapping({TAGGED_UNIT_URI: TAGGED_UNIT_SCHEMA})
        schema = asdf.schema.load_schema(TAGGED_UNIT_URI)
        # This should not raise an exception (check_schema will raise error)
        asdf.schema.check_schema(schema)
        # This should not raise exception (validate will raise error)
        asdf.schema.validate({"unit": unit}, schema=schema)