public void enumerateImportedFields(SDDocumentType documentType) {
        var search = this.schemas.stream()
                                 .filter(s -> s.getDocument() != null)
                                 .filter(s -> s.getDocument().getName().equals(documentType.getName()))
                                 .findFirst();
        if (search.isEmpty()) {
            return; // No imported fields present.
        }
        search.get().temporaryImportedFields().ifPresent(documentType::setTemporaryImportedFields);
    }
Enumerates and emplaces a set of all imported fields into a SDDocumentType from
its corresponding Search instance.
config-model/src/main/java/com/yahoo/schema/ImportedFieldsEnumerator.java