code: public void registerPropertyExclusion( Class target, String propertyName ) {
        if( target != null && propertyName != null ) {
           Set set = (Set) exclusionMap.get( target );
           if( set == null ){
              set = new HashSet();
              exclusionMap.put(  target, set );
           }
           if( !set.contains( propertyName )){
              set.add(propertyName );
           }
        }
     }
docs: Registers a exclusion for a target class.<br>
  [Java -&gt; JSON]
  
  @param target the class to use as key
  @param propertyName the property to be excluded