//The following example prints the male members contained in the
//collection roster with a pipeline that consists of the aggregate
//operations filter and forEach:
.filter(e -> e.getGender() == Person.Sex.MALE)
.forEach(e -> System.out.println(e.getName()));
//The following example calculates the average age of all male members
//contained in the collection roster with a pipeline that consists of the
//aggregate operations filter, mapToInt, and average:
double average = roster
.filter(p -> p.getGender() == Person.Sex.MALE)
A pipeline is a sequence of aggregate operations.
A pipeline contains the following components: a source, zero or more intermediate operations, a terminal operation.