code: def build_geojson_data(
      fname=os.path.join(
          os.path.dirname(__file__), "../..", "data/USA.json"
      )
  ):
      with open(fname, "r") as f:
          data = f.read()
      data = json.loads(data)
      data = json.dumps(data)
      data = base64.b64encode(data.encode("utf-8"))
      return "," + data.decode("utf-8")
  
file_path: dtale/tests/dtale/dash/test_custom_geojson.py
imports: import base64
  import json
  import mock
  import os
  import pandas
  import pytest
  from tests import ExitStack
  from tests.dtale import build_data_inst
  from tests.dtale.dash.test_dash import build_chart_params
  from tests.dtale.test_views import app
label_desc: Use image node_id 1 for calling a global function with example usage: build_geojson_data(fname) and returns: unknown