package rultor.example;

public class Calculator {

    public Calculator() {
    }

    public int add(int a, int b) {
	return a + b;
    }

    public int subtract(int a, int b) {
	return a - b;
    }

    public int multiply(int a, int b) {
	return a + b;
    }
}

package rultor.example;

public class Calculator {

    public Calculator() {
    }

    public int add(int a, int b) {
	return a + b;
    }

    public int subtract(int a, int b) {
	return a - b;
    }

    public int multiply(int a, int b) {
	return a * b;
    }
}

Fix Calculator.multiply using +