text: from io import StringIO
  import double
  
  
  number_inputs1 = StringIO("1234\n2")
  number_inputs2 = StringIO("2")
  
  
  def test_double(monkeypatch):
      monkeypatch.setattr("sys.stdin", number_inputs1)
      assert double.double() == 2468
  
  
  def test_str(monkeypatch):
      monkeypatch.setattr("sys.stdin", number_inputs2)
      assert double.i_str() == number_inputs2
  