private Optional<List<Snak>> processGDMQualifiedAttributes(final Statement statement) { final List<Snak> snakList = new ArrayList<>(); final Optional<Snak> optionalConfidence = processGDMQualifiedAttribute( CONFIDENCE_QUALIFIED_ATTRIBUTE_IDENTIFIER, statement.getConfidence()); final Optional<Snak> optionalEvidence = processGDMQualifiedAttribute( EVIDENCE_QUALIFIED_ATTRIBUTE_IDENTIFIER, statement.getEvidence()); final Optional<Snak> optionalOrder = processGDMQualifiedAttribute(ORDER_QUALIFIED_ATTRIBUTE_IDENTIFIER, statement.getOrder()); // D:SWARM statement uuid final Optional<Snak> optionalUUID = processGDMQualifiedAttribute( STATEMENT_UUID_QUALIFIED_ATTRIBUTE_IDENTIFIER, statement.getUUID()); addToSnakList(optionalConfidence, snakList); addToSnakList(optionalEvidence, snakList); addToSnakList(optionalOrder, snakList); addToSnakList(optionalUUID, snakList); if (snakList.isEmpty()) { return Optional.empty(); } return Optional.of(snakList); }