stacked bar chart

{
  "data": {"values": 
  [
        {"_submitted_by": "dalli",
          "INTRO_DISTRICT": [
            "Afgooye"
          ],
          "count": 1
        },
        {"_submitted_by": "dalli",
          "INTRO_DISTRICT": [
            "Awdaghle"
          ],
          "count": 15
        },
        {"_submitted_by": "dalli",
          "INTRO_DISTRICT": [
            "Belet_Weyne"
          ],
          "count": 14
        },
        {"_submitted_by": "dalli",
          "INTRO_DISTRICT": [
            "Howl Wadag"
          ],
          "count": 24
        },
        {"_submitted_by": "dalli",
          "INTRO_DISTRICT": [
            "Mataban"
          ],
          "count": 5
        }
      ]},
  "width": "container",
  "mark": {"type": "bar", "tooltip": true},
  "encoding": {
    "x": {
      "aggregate": "sum",
      "field": "count",
      "title": null,
      "axis": {"tickMinStep": 1}
    },
    "y": {"title": null, "field": "_submitted_by", "sort": "x"},
    "color": {"field": "INTRO_DISTRICT"}
  }
}