### Question:
Factorial { public int calc(int n) { int factorial = 1; for (int i = 1; i <= n; i++) { factorial *= i; } return factorial; }  int calc(int n);  }### Answer:
@Test public void factorialOfNumberFive() { Factorial factor = new Factorial(); int result = factor.calc(5); assertThat(result, is(120)); }
@Test public void factorialOfNumberOne() { Factorial factor = new Factorial(); int result = factor.calc(1); assertThat(result, is(1)); }