@FunctionalInterface
interface Assign {
double assess(int id, double percentage);
}

@FunctionalInterface
interface Assign {
double assess(int id, double percentage);
default double computeGrade(double cost) {
//implementation of computeGrade
}}

@FunctionalInterface
interface Assign {
double assess(int id, double percentage);
default double computeGrade(double cost) {
//implementation of computeGrade
}
static void display() {
//implementation of display
}
}

@FunctionalInterface
interface Assign {
double assess(int id, double percentage);
default double computeGrade(double cost) {
//implementation of computeGrade
}
static void display() {
//implementation of display
}
public String toString()
{
//Implementation of toString() method
}
}