FirstStream.swift

textField
	.rx //** <--- สำคัญมาก
	.text
	.orEmpty
	.asObservable()
	.subscribe(onNext: { (str) in
		print("TextField1 str: [\(str)]")
	})
	.disposed(by: disposeBag)

/* --[Console Output]--
  TextField1 str: []
  TextField1 str: [a]
  TextField1 str: [as]
  TextField1 str: [asd]
  TextField1 str: [asdf]
  TextField1 str: [asdfg]
  TextField1 str: [asdfgh]
  TextField1 str: [asdfghj]
  TextField1 str: [asdfghjk]
  TextField1 str: [asdfghjkl]
*/