You have created the following class called Course:

public class Course $\{$

private String code;

private long grade;

public String getCode$()\{$

return code;

$\}$

public void setCode$($String code$)\{$

this.code $=$ code;

$\}$

public long getGrade$()\{$

return grade;

$\}$

public void setGrade$($long grade$)\{$

this.grade $=$ grade;

$\}$

$\}$

How would you use aggregation in a Student class to show that a student has one or more courses?