text: import {createSet, execTest} from './perf'
  
  import {concat} from '../src/concat'
  import {concat as concat_naive} from '../src/naive/concat'
  
  const SIZE = 5000
  const TIMES = 5000
  
  const set1 = createSet(SIZE)
  const set2 = createSet(SIZE)
  const set3 = createSet(SIZE)
  
  console.log('\nStart testing concat()\n')
  
  execTest('concat()', TIMES, function () {
    [...concat(set1, set2, set3)]
  })
  
  execTest('naive concat()', TIMES, function () {
    [...concat_naive(set1, set2, set3)]
  })
  
  execTest('spread to array', TIMES, function () {
    [...[...set1, ...set2, ...set3]]
  })
  