public LoadedSubject loadFromFile(String collectionIdentifier, String subjectIdentifier) throws IOException {
        Path collection = this.container.resolve(collectionIdentifier);
        if (!Files.exists(collection)) {
            return null;
        }

        Path subject = collection.resolve(subjectIdentifier + ".json");
        return new LoadedSubject(subjectIdentifier, loadFromFile(subject).data);
    }
Loads a subject

@param collectionIdentifier the collection id
@param subjectIdentifier the subject id
@return a loaded subject
@throws IOException if the read fails
sponge/src/main/java/me/lucko/luckperms/sponge/service/model/persisted/SubjectStorage.java