@Test public void mulTwoNumbers() { double resultMul = mCalculator.mul(32d, 2d); assertThat(resultMul, is(equalTo(64d))); }
public double mul(double firstOperand, double secondOperand) { return firstOperand * secondOperand; }
Calculator { public double mul(double firstOperand, double secondOperand) { return firstOperand * secondOperand; } }
Calculator { public double mul(double firstOperand, double secondOperand) { return firstOperand * secondOperand; }  }
Calculator { public double mul(double firstOperand, double secondOperand) { return firstOperand * secondOperand; }  double add(double firstOperand, double secondOperand); double sub(double firstOperand, double secondOperand); double div(double firstOperand, double secondOperand); double mul(double firstOperand, double secondOperand); }
Calculator { public double mul(double firstOperand, double secondOperand) { return firstOperand * secondOperand; }  double add(double firstOperand, double secondOperand); double sub(double firstOperand, double secondOperand); double div(double firstOperand, double secondOperand); double mul(double firstOperand, double secondOperand);  }