in src/main/java/org/apache/sling/serviceusermapping/impl/ServiceUserMapperImpl.java [208:218]
protected synchronized void bindServiceUserValidator(final ServiceUserValidator serviceUserValidator, final Map<String, ?> props) {
userValidators.add(serviceUserValidator);
Object id = props.get(VALIDATOR_ID);
if (id instanceof String) {
presentUserValidators.add((String) id);
}
if (!requireValidation || !getPrincipalsValidators().isEmpty()) {
restartAllActiveServiceUserMappedServices();
}
}