track them start with the prefix "refs/notes/devtools". This helps make it
clear that these are meant to be read and written by automated tools.
When a field named "v" appears in one of these notes, it is used to denote
the version of the metadata format being used. If that field is missing, then
it defaults to the value 0, which corresponds to this initial verison of the
Code review requests are stored in the "refs/notes/devtools/reviews" ref, and