//XmiCasDeserializer.deserialize(new StringBufferInputStream(xml), cas2, true, sharedData2);
this.deserialize(xml, cas2, sharedData2, true, -1);
CasComparer.assertEquals(cas1, cas2);
//create Marker, add/modify fs and serialize in delta xmi format.
Marker marker = cas2.createMarker();
FSIndex cas2tIndex = cas2.getAnnotationIndex();
//create an annotation and add to index
AnnotationFS cas2newAnnot = cas2.createAnnotation(cas2.getAnnotationType(), 6, 8);
cas2.getIndexRepository().addFS(cas2newAnnot);