RasterCollection combinedRaster = new RasterCollection();
RasterConstraint rc = ass.getEvent().getConstraint(RasterConstraint.class);
if (rc != null)
combinedRaster.add(rc.getRaster().getForbidden());
EventRaster eventRaster = new EventRasterOneTreeMapImpl(slotsPerWeek);
// EventRaster eventRaster = new EventRasterTreeMapImpl(slotsPerWeek);
combinedRaster.add(eventRaster);
combinedRaster.add(dayRaster);
rasterMap.put(ass, new RasterEntry(eventRaster, combinedRaster));
}