code: static public CombinedRegistry getCombinedRegistry(CamelContext camelContext){
  		Registry reg = camelContext.getRegistry();
  		CombinedRegistry registry = null;
  		if (reg instanceof PropertyPlaceholderDelegateRegistry){
  			registry = (CombinedRegistry) ((PropertyPlaceholderDelegateRegistry)reg).getRegistry();
  		}else{ // should not go here
  			registry = (CombinedRegistry) reg;
  		}
  		return registry;
  	}
docs: Gets CombinedRegistry from CamelContext.<br>
  从CamelContext中得到CombinedRegistry类型的Registry。
  
  @param camelContext	The CamelContext must be based on CombinedRegistry, otherwise ClassCastException will be thrown.<br>
  这个context必须是采用CombinedRegistry类型的Registry的，否则会抛出格式转换异常。
  @return	The Registry that is of CombinedRegistry type.