@Test public void testGivenTwoNumbersWhenAddingThenResult() { int result = calculator.sum(2, 2); assertEquals(4, result); result = calculator.sum(8, 8); assertEquals(16, result); }
public int sum(final int augend, final int addend) { return augend + addend; }
Calculator { public int sum(final int augend, final int addend) { return augend + addend; } }
Calculator { public int sum(final int augend, final int addend) { return augend + addend; }  }
Calculator { public int sum(final int augend, final int addend) { return augend + addend; }  int sum(final int augend, final int addend); int product(final int multiplicand, final int multiplicier); }
Calculator { public int sum(final int augend, final int addend) { return augend + addend; }  int sum(final int augend, final int addend); int product(final int multiplicand, final int multiplicier);  }