code: public <T> Map<String, T> lookupByType(Class<T> type) {
  		Map<String, T> result = new HashMap<String, T>();
  		for (Registry reg: registryList){
  			Map<String, T> r = reg.lookupByType(type);
  			result.putAll(r);
  		}
  		return result;
  	}
docs: Looks up from all encapsulated Registry(s) one by one, and returns all the result found.<br>
  按次序从所封装的Registry中查找，并返回所有能找到的结果。
  <p>
  If no result can be found, an empty Map will be returned.
  <p>
  如果全都找不到，则返回一个空的Map。
  
  @see org.apache.camel.spi.Registry#lookupByType(java.lang.Class)