text: export default class Calculator {
    get env () {
      /* node-only */
      return `Node ${process.version}`
      /* end-node-only */
      /* browser-only */
      return 'Browser: ' + navigator.platform
      /* end-browser-only */
    }
  
    summation () {
      let total = 0
      Array.from(arguments).forEach(number => total += number)
      return total
    }
  
    average () {
      return this.summation(...arguments)/arguments.length
    }
  }
  