/** * Why would this mission be invalid with the given unit? * * @param aiUnit The <code>AIUnit</code> to test. * @return A reason why the mission would be invalid with the unit, or null if none found. */ private static String invalidMissionReason(AIUnit aiUnit) { String reason = invalidAIUnitReason(aiUnit); if (reason != null) return reason; final Unit unit = aiUnit.getUnit(); return (!unit.canCarryTreasure()) ? "unit-cannot-carry-treasure" : (unit.getTreasureAmount() <= 0) ? "unit-treasure-nonpositive" : null; }