HashMap<String, List<ResourceDTO>> hashMapResult = new HashMap<>(); // wynik

        List<ResourceRelationshipDTO> rrsDTIO = resources.stream().flatMap(e -> e.getRelationshipDTO().stream()).collect(Collectors.toList());

        rrsDTIO.forEach(e -> {
            String key = e.getResourceRefDTO().get().getId().get();
            if (!hashMapResult.containsKey(key)) {
                hashMapResult.put(
                        key,
                        resources.stream()
                                .filter(resource -> resource.getRelationshipDTO().stream().anyMatch(ref -> ref.getResourceRefDTO().equals(e.getResourceRefDTO())))
                                .filter(resource -> resource.getRelationshipDTO().stream().allMatch(resChar -> resChar.getResourceRelationshipCharacteristicDTO().get(0).getValue().equals("Device")) )
                                .collect(Collectors.toList())
                        );
            }
        });