docs: def prepare_geojson(geojson):
      """
      Modifies incoming GeoJSON to make it Elastic friendly. This means:
  
          1. CW orientation of polygons.
          2. Re-casting of Features and FeatureCollections to Geometry and
             GeometryCollections.
      """
      # TODO CW orientation.
      geojson = deepcopy(geojson)
  
      if geojson["type"] == "Feature":
          geojson = geojson["geometry"]
          if hasattr(geojson, 'properties'):
              del geojson['properties']
  
      if geojson["type"] == "FeatureCollection":
          geojson["type"] = "GeometryCollection"
          geojson["geometries"] = [
              feature["geometry"] for feature in geojson["features"]
          ]
          del geojson["features"]
  
      return geojson