def _load_compare_data(self, pull_request, enable_comments=True):

        """

        Load context data needed for generating compare diff

        :param pull_request:

        """

        c.org_repo = pull_request.org_repo

        (c.org_ref_type,

         c.org_ref_name,

         c.org_rev) = pull_request.org_ref.split(':')

        (c.other_ref_type,

         c.other_ref_name,

         c.other_rev) = pull_request.other_ref.split(':')

        org_scm_instance = c.org_repo.scm_instance # property with expensive cache invalidation check!!!

        c.cs_repo = c.org_repo

        c.cs_ranges = [org_scm_instance.get_changeset(x) for x in pull_request.revisions]

        c.cs_ranges_org = None # not stored and not important and moving target - could be calculated ...

        revs = [ctx.revision for ctx in reversed(c.cs_ranges)]

        c.jsdata = json.dumps(graph_data(org_scm_instance, revs))

        raw_ids = [x.raw_id for x in c.cs_ranges]