@Override
  public boolean equalsByReference(@NotNull KeyFMap o) {
    if (this == o) return true;
    if (!(o instanceof PairElementsFMap)) return false;

    PairElementsFMap<?,?> map = (PairElementsFMap<?,?>)o;

    return key1 == map.key1 && value1 == map.value1 && key2 == map.key2 && value2 == map.value2;
  }
@Override
  public boolean equalsByReference(@NotNull KeyFMap o)