attachment: refactoring bug fix
attachment: refactoring bug fix

doortts/forked-for-history,naver/yobi,violetag/demo,ihoneymon/yobi,oolso/yobi,bloodybear/yona,naver/yobi,doortts/fork-yobi,bloodybear/yona,oolso/yobi,doortts/fork-yobi,brainagenet/yobi,Limseunghwan/oss,ahb0327/yobi,ihoneymon/yobi,brainagenet/yobi,yona-projects/yona,ChangsungKim/TestRepository01,Limseunghwan/oss,yona-projects/yona,violetag/demo,doortts/fork-yobi,ahb0327/yobi,bloodybear/yona,ahb0327/yobi,doortts/forked-for-history,ChangsungKim/TestRepository01,brainagenet/yobi,oolso/yobi,naver/yobi,yona-projects/yona,doortts/fork-yobi,doortts/forked-for-history,ihoneymon/yobi,yona-projects/yona,Limseunghwan/oss,bloodybear/yona