pulkit added a comment. Looks like this was added so that extensions can replace using urllib2.Request. https://www.mercurial-scm.org/repo/hg/rev/00ecc894138d REPOSITORY rHG Mercurial REVISION DETAIL https://phab.mercurial-scm.org/D2723 To: indygreg, #hg-reviewers Cc: pulkit, mercurial-devel