// // emit

// const source = Rx.Observable.from([1, 2, 3, 4, 5])

// // add 10 to each value

// const example = source.map(val => val + 10)

// // out put: 11, 12, 13, 14, 15

// const subscribe = example.subscribe(val => console.log(val))

​

function multiplyByTen(input) {

  var output = Rx.Observable.create(function subscribe(observer) {

    input.subscribe({

      next: (v) => observer.next(10 * v),

      error: (err) => observer.error(10 * v),

      complete: () => observer.complete()

    })

  })

  return output

}

​

var input = Rx.Observable.from([1, 2, 3, 4])

var output = multiplyByTen(input)

output.subscribe(x => console.log('x' + x))