How do I start a review inside a Pull Request?

[Patrick Little]

Competitor tools offer a way to Start a Review within a pull/merge request. This means that I can merrily comment away, edit those comments, maybe delete some as my understanding of the code grows, and then finally submit my review to the author.

Instead, Bitbucket posts comments immediately, creating a major source of noise for the author.

I'm looking for how to do reviews in Bitbucket in the preferable way that the competitors do.