optaplanner-core/src/main/java/org/optaplanner/core/impl/score/director/easy/EasyScoreDirector.java
@Override
    public Score calculateScore() {
        variableListenerSupport.assertNotificationQueuesAreEmpty();
        Score score = easyScoreCalculator.calculateScore(workingSolution);
        if (score == null) {
            throw new IllegalStateException("The easyScoreCalculator (" + easyScoreCalculator.getClass()
                    + ") must return a non-null score (" + score + ") in the method calculateScore().");
        }
        if (workingInitScore != 0) {
            score = score.withInitScore(workingInitScore);
        }
        setCalculatedScore(score);
        return score;
    }
@Override
    public Score calculateScore() {
        variableListenerSupport.assertNotificationQueuesAreEmpty();
        Score score = easyScoreCalculator.calculateScore(workingSolution);
        if (score == null) {
            throw new IllegalStateException("The easyScoreCalculator (" + easyScoreCalculator.getClass()
                    + ") must return a non-null score (" + score + ") in the method calculateScore().");
        }
        if (workingInitScore != 0) {
            score = score.withInitScore(workingInitScore);
        }
        setCalculatedScore(score);
        return score;
    }
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