Java stream averagingInt by multiple parameters

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6

I have a class

static class Student {

    private String surname;
    private String firstName;
    private String secondName;
    private int yearOfBirth;
    private int course;
    private int groupNumber;
    private int mathGrade;
    private int engGrade;
    private int physicGrade;
    private int programmingGrade;
    private int chemistryGrade;

And there is a method that adds students to the map for the course

public Map<Integer, Double> averageInt(List<Student> students) {
            Map<Integer, Double> map2 = students.stream()
                    .collect(Collectors.groupingBy(Student::getCourse,
                            Collectors.averagingInt(Student::getEngGrade)));
            return map2;
        }

However, I need several average values ​​in one map at the same time. Not only engGrade, but also mathGrade, programmingGrade and so on. I think the code in this case should be in the format Map<Integer, List<Double>> but I don’t know how to do it. Tell me please

For example, I now display "Course = 1, average eng grade = ..."

And I need to display "Course = 1, average eng grade = ..., average math grade = ...", ie so that there are multiple Double values ​​in the map

java collections java-stream
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