@VisibleForTesting
    static String toString(@Nullable TaskManagerLocation location) {
        // '(unassigned)' being the default value is added to support backward-compatibility for the
        // deprecated fields
        return location != null ? location.getEndpoint() : "(unassigned)";
    }
@Test
    void testTaskManagerLocationFallbackHandling() {
        assertThat(JobExceptionsHandler.toString((TaskManagerLocation) null))
                .isEqualTo("(unassigned)");
    }