in src/main/java/org/apache/sling/jackrabbit/usermanager/impl/resource/PrincipalResource.java [76:85]
public <T> T adaptTo(Class<T> type) {
if (type == Map.class || type == ValueMap.class) {
ValueMap valueMap = new ValueMapDecorator(Collections.emptyMap());
return type.cast(valueMap);
} else if (type == Principal.class) {
return type.cast(principal);
}
return super.adaptTo(type);
}