optaplanner-core/src/main/java/org/optaplanner/core/impl/solver/termination/BasicPlumbingTermination.java
public synchronized <Solution_> boolean addProblemFactChanges(List<ProblemFactChange<Solution_>> problemFactChangeList) {
        boolean added = problemFactChangeQueue.addAll(problemFactChangeList);
        notifyAll();
        return added;
    }
public synchronized <Solution_> boolean addProblemFactChanges(List<ProblemFactChange<Solution_>> problemFactChangeList) {
        boolean added = problemFactChangeQueue.addAll(problemFactChangeList);
        notifyAll();
        return added;
    }
Concurrency note: unblocks {@link #waitForRestartSolverDecision()}.
@param problemFactChangeList never null
@return as specified by {@link Collection#add}