@Contract(value = "null -> false", pure = true)
    @Override
    public boolean equals(@Nullable Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
      StoredData<?> data = (StoredData<?>)o;
      return Objects.equals(getElement(), data.getElement()) &&
             Objects.equals(getDetails(), data.getDetails());
    }
@Contract(value = "null -> false", pure = true)
    @Override
    public boolean equals(@Nullable Object o)