guage, see docstring in phabread
    for details.

    A "Differential Revision dict" looks like:

        {
            "activeDiffPHID": "PHID-DIFF-xoqnjkobbm6k4dk6hi72",
            "authorPHID": "PHID-USER-tv3ohwc4v4jeu34otlye",
            "auxiliary": {
              "phabricator:depends-on": [
                "PHID-DREV-gbapp366kutjebt7agcd"
              ]
              "phabricator:projects": [],
            },
            "branch": "default",
            "ccs": [],
            "commits": [],
            "dateCreated": "1499181406",
            "dateModified": "1499182103",
            "diffs": [
              "3",
              "4",
            ],
            "hashes": [],
            "id": "2",
            "lineCount": "2",
            "phid": "PHID-DREV-672qvysjcczopag46qty",
            "properties": {},
            "repositoryPHID": "PHID-REPO-hub2hx62ieuqeheznasv",
            "reviewers": [],
            "sourcePath": null
            "status": "0",
            "statusName": "Needs Review",
            "summary": "",
            "testPlan": "",
            "title": "example",
            "uri": "https://phab.example.com/D2",
        }
    c