}

    public Attribute<?> getAttribute() {
        return attribute;
    }

    public Object getLeftValue() {
        return leftValue;
    }

    public Object getRightValue() {
        return rightValue;
    }

                Attribute<?> attribute = mergeError.getAttribute();
                Object constraintValue = mergeError.getLeftValue();
                Object dependencyValue = mergeError.getRightValue();
                return "Inconsistency between attributes of a constraint and a dependency, on attribute '" + attribute + "' : dependency requires '" + dependencyValue + "' while constraint required '" + constraintValue + "'";