### Question:
AdditionOperation 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 AdditionOperation(); assertThat(op.calculate(5, 2)).isEqualTo(7); assertThat(op.calculate(10, 5)).isEqualTo(15); assertThat(op.calculate(4, 2)).isEqualTo(6); }