if (roots == FileSystemSnapshot.EMPTY) {
            return strategy.getEmptyFingerprint();
        }

        ImmutableMultimap<String, HashCode> rootHashes = SnapshotUtil.getRootHashes(roots);
        Map<String, FileSystemLocationFingerprint> fingerprints;
        if (candidate != null

     */
    FingerprintHashingStrategy getHashingStrategy();

    String getIdentifier();

    CurrentFileCollectionFingerprint getEmptyFingerprint();

    HashCode getConfigurationHash();

    }

    @Override
    public CurrentFileCollectionFingerprint empty() {
        return fingerprintingStrategy.getEmptyFingerprint();
    }

        this.configurationHash = hasher.hash();
    }

    @Override
    public String getIdentifier() {
        return identifier;
    }

    @Override
    public CurrentFileCollectionFingerprint getEmptyFingerprint() {
        return emptyFingerprint;
    }

    @Nullable
    protected HashCode getNormalizedContentHash(FileSystemLocationSnapshot snapshot, FileSystemLocationSnapshotHasher normalizedContentHasher) {