input: Write a function to concatenate two strings, "Hello" and "World", with a space in between and print the result.
  
  
  def concatenate_and_print():
      string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)
  
  assert concatenate_and_print() == None
  
output: def concatenate_and_print():
      string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)