Can we still denoise after a render in 2.79?


According to THE INTERNET, there’s a way to denoise your render in the compositor in the 2.77(?) buildbot(?) build, provided a checkbox labeled as “keep denoising data” is checked before the render is started. I can’t find the box anywhere in 2.79, nor the denoising node in the compositor. Is there still a procedure to denoise after rendering?