code: public static Restrictor or(Restrictor c1, Restrictor c2) {
  		return new LogicRestrictor(c1, c2, RestrictType.or);
  	}
docs: 对两个ICriterion进行 "逻辑或" 合并
  @param c1 Restrictor left
  @param c2 Restrictor right
  @return Restrictor