Forward-looking: Foldable phones might not have set the world on fire, but companies aren't giving up on the design. Following Samsung's unveiling of the Galaxy Z Fold 2, an Android document suggests Google will release a foldable Pixel device next year.

The internal document, obtained by 9to5Google, lists all launched Pixels since the Pixel 2 and several unannounced models, including the Pixel 5a (the Pixel 5 was recently announced alongside the Pixel 4a), and three in-development devices with the codenames "raven," "oriole," and "passport."

It's speculated that "raven" and "oriole" are Pixel 6 models, but "passport" is referred to explicitly as being foldable. All three are slated to arrive in the fourth quarter of next year, by which time Samsung will have likely released another folding phone.

This isn't the first time we've heard of Google's plans for a foldable. Last year, in the wake of the Galaxy Fold debacle, the company said it had been prototyping the technology for some time but wasn't in a hurry to bring a device to market.

"We're prototyping foldable displays and many other new hardware technologies, and have no related product announcements to make at this time," said Mario Queiroz, the former head of Pixel development at Google, at the time. "The use case is going to need to be something where you go, 'Hey, I definitely need to have this.' Right now, you don't need to have a foldable. It's kind of a 'nice-to-have.'"

The document also states that the Pixel 4a 5G model and Pixel 5 will arrive in October (possibly Oct 8th, based on an official blog post), giving a more precise timeframe than Google's "fall" date. The Pixel 5a, meanwhile, is slated for a "Q2 2021" release.

It might not be able to match the likes of Samsung and Apple, but Google had its best Pixel sales ever last year, with the phones shifting 7.2 million units---more than what OnePlus managed.