List<Person> peoples = Arrays.asList(
new Person(12, "孙悟空"),
new Person(null, "猪八戒"),
new Person(12, "孙悟空")
);
Integer totalInteger = EnhanceStream.mapToNonNullSum(peoples, Person::getAge);
Console.log(totalInteger);
List<Long> longs = Arrays.asList(1L, 2L, 3L);
Long totalLong = EnhanceStream.mapToNonNullSum(longs, Function.identity());
Console.log(totalLong);
List<Double> doubles = Arrays.asList(1.1d, 2.2d, 3.3d);
Double totalDouble = EnhanceStream.mapToNonNullSum(doubles, Function.identity());
Console.log(totalDouble);