some fake geojson

squares.geojson

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "title": "west",
        "avg_income": 100000
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -125.5078125,
              23.885837699862005
            ],
            [
              -104.0625,
              23.885837699862005
            ],
            [
              -104.0625,
              45.089035564831036
            ],
            [
              -125.5078125,
              45.089035564831036
            ],
            [
              -125.5078125,
              23.885837699862005
            ]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "title": "east",
        "avg_income": 80000
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -96.6796875,
              24.206889622398023
            ],
            [
              -74.53125,
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            ],
            [
              -74.53125,
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            ],
            [
              -96.6796875,
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            ],
            [
              -96.6796875,
              24.206889622398023
            ]
          ]
        ]
      }
    }
  ]
}