src/edu/kit/informatik/campusmanagement/CampusManagement.java
/**
     * Returns the student with the specified student number.
     * 
     * @param  studentnumber the student number
     * @return the student
     * @throws IllegalArgumentException if the student does not exist
     */
Returns the student with the specified student number.

@param  studentnumber the student number
@return the student
@throws IllegalArgumentException if the student does not exist
Returns the student with the specified student number . @param studentnumber the student number @return the student @throws IllegalArgumentException if the student does not exist
public Student student(
            final int studentnumber) {
        return Optional.of(new Student(null, null, studentnumber)).map(students::get)
                .orElseThrow(() -> noSuch(Student.class, studentnumber));
    }
public Student student ( final int studentnumber ) { return Optional . of ( new Student ( null , null , studentnumber ) ) . map ( students :: get ) . orElseThrow ( ( ) -> noSuch ( Student . class , studentnumber ) ) ; }
Returns the student with the specified student number.
Returns the student with the specified student number .
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