code: def test_choropleth_get_by_key():
      geojson_data = {
          "id": "0",
          "type": "Feature",
          "properties": {"idx": 0, "value": 78.0},
          "geometry": {
              "type": "Polygon",
              "coordinates": [
                  [
                      [1, 2],
                      [3, 4],
                  ]
              ],
          },
      }
  
      # Test with string path in key_on
      assert Choropleth._get_by_key(geojson_data, "properties.idx") == 0
      assert (
          Choropleth._get_by_key(geojson_data, "properties.value")
          == 78.0
      )
  
      # Test with combined string path and numerical index in key_on
      assert Choropleth._get_by_key(
          geojson_data, "geometry.coordinates.0.0"
      ) == [1, 2]
  
imports: import json
  import os
  import warnings
  import pytest
  from branca.element import Element
  import folium
  from folium import Choropleth, ClickForMarker, GeoJson, Map, Popup
label_desc: Use image node_id 16 for calling a global function with example usage: test_choropleth_get_by_key() without return types