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: 23 years ago, Chris Patten, the outgoing Governor of Hong Kong, made an emotional farewell speech as Britain handed over its prized colony to China. With the Royal Yacht Britannia purring away in the harbour as the ultimate imperial getaway vehicle, he said, "Now Hong Kong people are going to run Hong Kong. That is the promise and that is the unshakable destiny."

Cockroach: Ai Weiwei's new documentary on last year's Hong Kong protests ★★★★☆