input: from typing import List
  
  def double_add(num1: int, num2: int) -> int:
      """ Adds two numbers and then doubles the result.
      >>> double_add(1, 2)
      6
      >>> double_add(0, 0)
      0
      >>> double_add(-1, -2)
      -6
      """
output:     return (num1 + num2) * 2