Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The self-driving bubble car developed by Waymo, part of Google's parent firm Alphabet, is to be phased out, the firm has announced.

Waymo retires Firefly driverless car