123456789101112131415
import {includes} from './includes'import {cloneList} from './_internals/cloneList'
export function union(x, y) {  if (arguments.length === 1) return _y => union(x, _y)
  const toReturn = cloneList(x)
  y.forEach(yInstance => {    if (!includes(yInstance, x)) toReturn.push(yInstance)  })
  return toReturn}