input: 
  def print_hello_world() -> None:
      """Given two strings "Hello" and "World", this function concatenates them with a space and prints the result.
      >>> print_hello_world()
      Hello World
      """
      string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)
  
output:     string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)