* <code>def</code>.
*/
private Filter addCachingWrapperFilter(Filter filter, FilterDef def) {
if ( cacheResults( def.getCacheMode() ) ) {
int cachingWrapperFilterSize = searchFactoryImplementor.getFilterCacheBitResultsSize();
filter = new CachingWrapperFilter( filter, cachingWrapperFilterSize );
}
return filter;
}