public Container documentProcessor(String chainName, Class<? extends DocumentProcessor> docproc, ConfigInstance... configs) {
                return documentProcessor(docproc.getName(), chainName, docproc, configs);
            }
@param chainName chain name to add docproc
@param docproc   add this docproc to the document processing chain
@param configs   local docproc configs
@return builder
application/src/main/java/com/yahoo/application/Application.java