text: const DxManagementService = require('./DxManagementService')
  const getAuctionRepo = require('../../repositories/AuctionRepo')
  const getEthereumRepo = require('../../repositories/EthereumRepo')
  
  let instance, instancePromise
  
  async function _getInstance () {
    const [auctionRepo, ethereumRepo] = await Promise.all([
      getAuctionRepo(),
      getEthereumRepo()
    ])
    return new DxManagementService({
      auctionRepo,
      ethereumRepo
    })
  }
  
  module.exports = async () => {
    if (!instance) {
      if (!instancePromise) {
        instancePromise = _getInstance()
      }
  
      instance = await instancePromise
    }
  
    return instance
  }
  