details.source.cancelExecution();
            }
        }

        public void abortAllAndFail(Throwable t) {
            coordinationService.assertHasStateLock();
            for (PlanDetails details : queues) {
                details.source.abortAllAndFail(t);
            }
            coordinationService.notifyStateChange();
        }

        public boolean nothingQueued() {

     */
    Selection<T> selectNext();

    void finishedExecuting(T item, @Nullable Throwable failure);

    void abortAllAndFail(Throwable t);

    void cancelExecution();

    /**
     * Has all execution completed?
     *
     * <p>When this method returns {@code true}, there is no further work to start and no work in progress.</p>

                abortExecution();
            }
        }
    }

    private boolean abortExecution() {
        return abortExecution(false);
    }

    @Override
    public void abortAllAndFail(Throwable t) {
        lockCoordinator.assertHasStateLock();
        failures.add(t);
        abortExecution(true);
    }

    @Override
    public void cancelExecution() {