### Question:
Complexity { public Complexity add(final Complexity other) { return new Complexity( getMcCabe() + other.getMcCabe(), getHalstead().add(other.getHalstead())); } Complexity(final int pMcCabe, @NonNull final Halstead pHalstead);  Complexity(final Complexity other); Complexity add(final Complexity other); static final Complexity EMPTY_COMPLEXITY; }### Answer:
@Test public void add() { Complexity add = complexity.add(complexity); assertThat(add.getMcCabe()).isEqualTo(18); }