Caused by: java.lang.IllegalStateException: The class (class [Lorg.optaplannerdelirium.santagiftmatching.domain.Child;) should have a no-arg constructor to create a planning clone.
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner.lambda$retrieveCachedConstructor$0(FieldAccessingSolutionCloner.java:93)
	at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner.retrieveCachedConstructor(FieldAccessingSolutionCloner.java:88)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner$FieldAccessingSolutionClonerRun.constructClone(FieldAccessingSolutionCloner.java:250)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner$FieldAccessingSolutionClonerRun.clone(FieldAccessingSolutionCloner.java:242)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner$FieldAccessingSolutionClonerRun.process(FieldAccessingSolutionCloner.java:296)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner$FieldAccessingSolutionClonerRun.processQueue(FieldAccessingSolutionCloner.java:285)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner$FieldAccessingSolutionClonerRun.cloneSolution(FieldAccessingSolutionCloner.java:228)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner.cloneSolution(FieldAccessingSolutionCloner.java:77)
	at org.optaplanner.core.impl.score.director.AbstractScoreDirector.cloneSolution(AbstractScoreDirector.java:184)
	at org.optaplanner.core.impl.solver.scope.DefaultSolverScope.setWorkingSolutionFromBestSolution(DefaultSolverScope.java:225)
	at org.optaplanner.core.impl.solver.AbstractSolver.solvingStarted(AbstractSolver.java:75)
	at org.optaplanner.core.impl.solver.DefaultSolver.solvingStarted(DefaultSolver.java:186)
	at org.optaplanner.core.impl.solver.DefaultSolver.solve(DefaultSolver.java:166)
	at org.optaplanner.examples.common.business.SolutionBusiness.solve(SolutionBusiness.java:329)
	at org.optaplanner.examples.common.swingui.SolverAndPersistenceFrame$SolveWorker.doInBackground(SolverAndPersistenceFrame.java:324)
	at javax.swing.SwingWorker$1.call(SwingWorker.java:295)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at javax.swing.SwingWorker.run(SwingWorker.java:334)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NoSuchMethodException: [Lorg.optaplannerdelirium.santagiftmatching.domain.Child;.<init>()
	at java.lang.Class.getConstructor0(Class.java:3082)
	at java.lang.Class.getDeclaredConstructor(Class.java:2178)
	at org.optaplanner.core.impl.domain.solution.cloner.FieldAccessingSolutionCloner.lambda$retrieveCachedConstructor$0(FieldAccessingSolutionCloner.java:91)
	... 21 more