### Question:
FusionIndexAccessor extends FusionIndexBase<IndexAccessor> implements IndexAccessor { @Override public boolean isDirty() { return Iterables.stream( instanceSelector.transform( IndexAccessor::isDirty ) ).anyMatch( Boolean::booleanValue ); } FusionIndexAccessor( SlotSelector slotSelector,
            InstanceSelector<IndexAccessor> instanceSelector,
            StoreIndexDescriptor descriptor,
            IndexDropAction dropAction ); @Override void drop(); @Override IndexUpdater newUpdater( IndexUpdateMode mode ); @Override void force( IOLimiter ioLimiter ); @Override void refresh(); @Override void close(); @Override IndexReader newReader(); @Override BoundedIterable<Long> newAllEntriesReader(); @Override ResourceIterator<File> snapshotFiles(); @Override Map<String,Value> indexConfig(); @Override void verifyDeferredConstraints( NodePropertyAccessor nodePropertyAccessor ); @Override boolean isDirty(); @Override void validateBeforeCommit( Value[] tuple ); @Override boolean consistencyCheck( ReporterFactory reporterFactory );  }### Answer:
@Test public void fusionIndexIsDirtyWhenAnyIsDirty() { for ( IndexAccessor dirtyAccessor : aliveAccessors ) { for ( IndexAccessor aliveAccessor : aliveAccessors ) { when( aliveAccessor.isDirty() ).thenReturn( aliveAccessor == dirtyAccessor ); } assertTrue( fusionIndexAccessor.isDirty() ); } }