docs: private <T> Class<? extends T> getObjectFromClassMap(String id, Map<String, Object> classMap)
      {
          Object obj = classMap.get(id);
          
          if(obj == null)
          {
              return null;    //object for this id wasn't found on the map
          }
          
          if(obj instanceof Class<?>)
          {
              return (Class<? extends T>)obj;
          }
          else if (obj instanceof String )
          {
              Class<?> clazz = ClassUtils.simpleClassForName((String)obj);
              classMap.put(id, clazz);
              return (Class<? extends T>)clazz;
          }
          
          //object stored in the map for this id is an invalid type.  remove it and return null
          classMap.remove(id);
          return null;        
      }