b) Write JAVA codes for the following conditions: i) Declare a simple interface named as My Interface, the interface consists of two methods. The first method is calculate method that receive two int parameters and return an int value. The second method id greet method that does not receive any parameters and does not return any value. ii) Create class Demo that make use of My Interface. iii) Create class TestInterface to test conditions in (i) and (II). Show polymorphism technique