@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((answer == null) ? 0 : answer.hashCode());
		result = prime * result
				+ ((answerInfo == null) ? 0 : answerInfo.hashCode());
		result = prime * result + ((choice == null) ? 0 : choice.hashCode());
		result = prime * result
				+ ((frequence == null) ? 0 : frequence.hashCode());
		result = prime * result
				+ ((historyDate == null) ? 0 : historyDate.hashCode());
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		result = prime * result
				+ ((question == null) ? 0 : question.hashCode());
		result = prime * result + ((taken == null) ? 0 : taken.hashCode());
		return result;
	}