input: 
  def double_add(num1: int, num2: int) -> int:
      """
      Adds two numbers and then doubles the result.
      
      >>> double_add(2, 3)
      10
      >>> double_add(-1, 4)
      6
      """
      return (num1 + num2) * 2
  
output:     return (num1 + num2) * 2