e ModelWriter format: {}, service: {}, nativeType: {}",             new Object[]{mediaType, reference,                 nativeType != null ? nativeType.getClass().getName() : "none"});         Map<MediaType,List<ServiceReference>> typeWriters = writers.get(null);         updateTypeWriter(typeWriters, mediaType, reference);         if(nativeType != null){             typeWriters = writers.get(nativeType.getName());             if(typeWriters != null){                 updateTypeWriter(typeWriters, mediaType, reference);             }         }         cache.clear(); //clear the cache after a change     }      /**      * @param typeWriters      * @param mediaType      * @param reference      */     private void updateTypeWriter(Map<MediaType,List<ServiceReference>> typeWriters,             MediaType mediaType,             ServiceReference reference) {         List<ServiceReference> l = typeWriters.get(mediaType);         if(l != null && l.