express - node.js module require() twice -- (relative path) -

why qrchannelservice module required twice(mongoose throw overwritemethod error), why didn't cached ?

qrchannelservice path: mit/src/modules/qrchannel/services/qrchannelservice.js

require

path1: mit/src/controllers/api/qr.js var qrcodeservice = require('../../modules/qrchannel/services/qrchannelservice');

path2: mit/src/modules/qrchannel/common/qrhandlerdispather.js var qrchannelservice = require('../services/qrchannelservice');