@Test public void whenMultipleFirstAndSecondThenResultSix() { Calculator calc = new Calculator(); calc.multiple(3d, 2d); assertThat(calc.result, is(6d)); }
public void multiple (double first, double second) { this.result = first * second; }
Calculator { public void multiple (double first, double second) { this.result = first * second; } }
Calculator { public void multiple (double first, double second) { this.result = first * second; }  }
Calculator { public void multiple (double first, double second) { this.result = first * second; }  void add(double first, double second); void substtruct(double first, double second); void div(double first, double second); void multiple(double first, double second); }
Calculator { public void multiple (double first, double second) { this.result = first * second; }  void add(double first, double second); void substtruct(double first, double second); void div(double first, double second); void multiple(double first, double second); public double result; }