Description: Batching chunks

java.lang.NullPointerException: Cannot invoke "der.b()" because the return value of "des.a()" is null
	at des.c(SourceFile:47)
	at epw$c$b.a(SourceFile:503)
	at epw$c$b.a(SourceFile:447)
	at epw.a(SourceFile:132)
	at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1146)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1806)
	at java.base/java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1792)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:295)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1016)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1665)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1598)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)