### Question:
MultiplicationOperation implements Operation { @Override public int calculate(int a, int b) { return a * b; }  @Override int calculate(int a, int b); @Override String name();  }### Answer:
@Test public void testModulus() { Operation op = new MultiplicationOperation(); assertThat(op.calculate(5, 2)).isEqualTo(10); assertThat(op.calculate(10, 5)).isEqualTo(50); assertThat(op.calculate(4, 2)).isEqualTo(8); }