code: public static ParamProcessor newInstance(ParamType type, String listSeparator){
          switch(type){
              case COOKIE:
                  return listSeparator != null ? new CollectionMergingCookieParamProcessor(listSeparator) : DefaultCookieParamProcessor.INSTANCE;
              default:
                  return listSeparator != null ? new CollectionMergingParamProcessor(listSeparator) : DefaultParamProcessor.INSTANCE;
          }
      }
docs: Returns an instance of a param processor.
  @param type parameter type
  @param listSeparator list separator if applicable, otherwise null
  @return instance of param processor