One more take at the darts problem. This time, we will introduce the rule that the final, winning dart must be a double. Since it is now harder to figure out how to win, define the function darts_doubleout_named(total) to return a string naming the darts if there is a way to reach total with the last dart being a double, and return None if there is no such way. If there are multiple ways, choose the way that first has the fewest number of darts, and second is in the highest numeric order (highest dart first, etc.).