hourly_totals 是psented作为一个字符串到另一个对象一个小时再$ P $的对象，以地图＆LT;弦乐，T＆GT; ，其中T是一个POJO类，再presenting数据一小时，看起来像一个自然的选择。

hourly_totals is an object from an hour represented as a string to another object, to Map<String,T> , where T is a POJO class representing the data for one hour, would look like a natural choice.