for (int i = 0; i < 10; i++) {
      builder.put(i, i);
    }
    Object[] builderArrayAfterPuts = builder.alternatingKeysAndValues;
    RegularImmutableBiMap<Integer, Integer> map =
        (RegularImmutableBiMap<Integer, Integer>) builder.build();
    Object[] mapInternalArray = map.alternatingKeysAndValues;
    assertThat(builderArrayAfterPuts).isSameInstanceAs(builderArray);