Merge branch 'master' of github.com:dkpro/dkpro-core

# By Manuel R. Ciosici
# Via Manuel R. Ciosici (1) and Richard Eckart de Castilho (1)
* 'master' of github.com:dkpro/dkpro-core:
  prevent the iterator from throwing a ConcurrentModificationExceptions

de.tudarmstadt.ukp.dkpro.core.castransformation-asl/src/main/java/de/tudarmstadt/ukp/dkpro/core/castransformation/Backmapper.java

@@ -132,7 +132,7 @@ void updateOffsets(
 					"No mapping found from ["+from+"] to ["+to+"] on ["+baseCas.hashCode()+"]"));
 		}
 
-		FSIndex<Annotation> idx = targetView.getAnnotationIndex();
+		FSIndex<Annotation> idx = targetView.getAnnotationIndex().withSnapshotIterators();
 		FSIterator<Annotation> it = idx.iterator();
 		TypeSystem typeSystem = targetView.getTypeSystem();
 		Type annotationType = typeSystem.getType(CAS.TYPE_NAME_ANNOTATION);