Scheduled hover info update task is not cancelled properly when canvas participant is removed
DEBUG [2019-11-20 13:34:53,672] org.simantics.district.network.ui.participants.DynamicVisualisationContributionsParticipant: Interrupted hovering
org.simantics.db.exception.NoSingleResultException: No single object for subject [null - [id=$1552619]] and relation [InstanceOf - [id=$8193]] [resultCount=0]
at org.simantics.db.impl.graph.ReadGraphImpl.getSingleObject(ReadGraphImpl.java:910)
at org.simantics.district.network.ui.participants.DynamicVisualisationContributionsParticipant$2$1.run(DynamicVisualisationContributionsParticipant.java:172)
at org.simantics.db.common.request.ReadRequest.perform(ReadRequest.java:21)
at fi.vtt.simantics.procore.internal.SessionImplSocket$6.run(SessionImplSocket.java:1547)
at fi.vtt.simantics.procore.internal.SessionRequestManager$6.run(SessionRequestManager.java:315)
at org.simantics.db.impl.query.QueryThread.run(QueryThread.java:251)
Wrapped by: java.util.concurrent.ExecutionException: org.simantics.db.exception.NoSingleResultException: No single object for subject [null - [id=$1552619]] and relation [InstanceOf - [id=$8193]] [resultCount=0]
at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
at org.simantics.district.network.ui.participants.DynamicVisualisationContributionsParticipant$2.lambda$0(DynamicVisualisationContributionsParticipant.java:210)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
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)