input: Write a function to generate a Python program that adds two numbers and then doubles the result. The function should take two arguments and return the final computed value by performing the specified operations.
  
  def double_add(num1, num2): 
      return (num1 + num2) * 2
  
  assert double_add(3, 4) == 14
  assert double_add(0, 0) == 0
  assert double_add(-1, 1) == 0
  assert double_add(5, 5) == 20
  assert double_add(-2, -2) == -8
output: def double_add(num1, num2): 
      return (num1 + num2) * 2