}

    @Nullable
    private Object getCandidateValue(int c, int a) {
        return candidateValues[getValueIndex(c, a)];
    }

    private void setCandidateValue(int c, int a, @Nullable Object value) {
        candidateValues[getValueIndex(c, a)] = value;
    }

    private int getValueIndex(int c, int a) {
        return c * requestedAttributes.size() + a;
    }

    private enum MatchResult {