Race condition when quickly toggling neurons with synapses

This exception was thrown on several threads at the same time, it seems that the contains() method in FragmentsInSelectedSegments needs some sort of synchronization:

java.util.concurrent.ExecutionException: java.lang.ArrayIndexOutOfBoundsException: 45
    at net.imglib2.cache.ref.SoftRefLoaderCache.get(SoftRefLoaderCache.java:112)
    at net.imglib2.cache.util.LoaderCacheAsCacheAdapter.get(LoaderCacheAsCacheAdapter.java:43)
    at net.imglib2.cache.ref.WeakRefVolatileCache.getBlocking(WeakRefVolatileCache.java:451)
    at net.imglib2.cache.ref.WeakRefVolatileCache.access$000(WeakRefVolatileCache.java:20)
    at net.imglib2.cache.ref.WeakRefVolatileCache$FetchEntry.call(WeakRefVolatileCache.java:498)
    at net.imglib2.cache.ref.WeakRefVolatileCache$FetchEntry.call(WeakRefVolatileCache.java:475)
    at net.imglib2.cache.queue.FetcherThreads$Fetcher.run(FetcherThreads.java:177)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 45
    at gnu.trove.impl.hash.TLongHash.indexRehashed(TLongHash.java:233)
    at gnu.trove.impl.hash.TLongHash.index(TLongHash.java:219)
    at gnu.trove.impl.hash.TLongHash.contains(TLongHash.java:163)
    at org.janelia.saalfeldlab.paintera.control.selection.FragmentsInSelectedSegments.contains(FragmentsInSelectedSegments.java:47)
    at org.janelia.saalfeldlab.paintera.state.IntersectingSourceState.lambda$checkForLabelMultisetType$10(IntersectingSourceState.java:288)
    at org.janelia.saalfeldlab.paintera.state.LabelIntersectionCellLoader.load(LabelIntersectionCellLoader.java:73)
    at net.imglib2.cache.img.LoadedCellCacheLoader.get(LoadedCellCacheLoader.java:91)
    at net.imglib2.cache.img.LoadedCellCacheLoader.get(LoadedCellCacheLoader.java:51)
    at net.imglib2.cache.ref.SoftRefLoaderCache.get(SoftRefLoaderCache.java:102)
    ... 6 more

saalfeldlab / paintera

Race condition when quickly toggling neurons with synapses #344