Washington, DC metro area - location with a boundary

{
  "resourceType" : "Location",
  "id" : "wash-dc-metro",
  "meta" : {
    "profile" : ["http://hl7.org/fhir/uv/vhdir/StructureDefinition/vhdir-location"]
  },
  "extension" : [{
    "url" : "http://hl7.org/fhir/StructureDefinition/location-boundary-geojson",
    "valueAttachment" : {
      "contentType" : "application/geo+json",
      "data" : "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",
      "url" : "https://github.com/OpenDataDE/State-zip-code-GeoJSON/raw/master/dc_district_of_columbia_zip_codes_geo.min.json",
      "size" : "389"
    }
  }],
  "status" : "active",
  "name" : "Washington, DC metro area",
  "form" : {
    "coding" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/location-physical-type",
      "code" : "area",
      "display" : "Area"
    }]
  }
}