Error handling and default values for domain attributes #57
Description
When defining a class with a domain attribute, e.g. class Plant (domain Double moisture), the attribute must be present in the construct SPARQL query. If not, the reasoner will throw an inconsistency error, materializing it as null. Even if the attribute gets then assigned later manually or with a method, the reasoner will still consider it null and throw the error.
There should be a better handling or a way to create default values when constructing the object to avoid encountering the error.