{
    "description": "Handle a not-ok ismaster response", 
    "phases": [
        {
            "outcome": {
                "servers": {
                    "a:27017": {
                        "setName": null, 
                        "type": "Unknown"
                    }
                }, 
                "setName": null, 
                "topologyType": "Single"
            }, 
            "responses": [
                [
                    "a:27017", 
                    {
                        "ismaster": true, 
                        "ok": 1
                    }
                ], 
                [
                    "a:27017", 
                    {
                        "ismaster": true, 
                        "ok": 0
                    }
                ]
            ]
        }
    ], 
    "uri": "mongodb://a"
}