MapExtra extends Extra<A, F> { @Nullable protected V get(K key) { if (key == null) return null; Object[] state = state(); int i = indexOfExistingKey(state, key); return i != -1 ? (V) state[i + 1] : null; } protected  MapExtra(F factory);   }
@Test public void get_ignored_if_unconfigured() { assertThat(extra.get("three")).isNull(); }
@Test public void get_null_if_not_set() { assertThat(extra.get("1")).isNull(); }