async function findInCollection(collection, repeat){
  const array = Array.from(Array(repeat).keys())

  const promises = array.map(async (i) => {
    return new Promise((resolve, reject) => {
      collection.find({}).toArray((err, docs) => {
        console.log(`query ${i} => ${docs.length}`)
        err ? reject(err) : resolve(docs)
      })
    })
  })

  Promise.all(promises).then(console.log('terminouuu'))

}