input: from typing import Union
  
  def double_add(num1: Union[int, float], num2: Union[int, float]) -> Union[int, float]:
      """Add two numbers and then double the result.
      >>> double_add(2, 3)
      10
      >>> double_add(5.0, 1.5)
      13.0
      >>> double_add(0, 0)
      0
      """
      return (num1 + num2) * 2
output:     return (num1 + num2) * 2