public interface Constants {
    /**
     *  状态
     */
    interface State {
    Integer WAITING_CHOOSE_MEDIATOR = 10;
	Integer WAITING_ACCEPT = 20;
	Integer MEDIATING = 30;
	Integer WAITING_PARTY_CONFIRM = 40;
	Integer CLOSED_SUCCESS = 51;
    }


    /**
     *  角色
     */
    enum Role{
		Student, Teacher
	}