code: def test_datetime(datetime_value, engine, pretty):
      value = build_test_dict(datetime_value)
      result = pio.to_json_plotly(value, engine=engine, pretty=pretty)
      expected = build_test_dict_string(
          '"{}"'.format(isoformat_test(datetime_value))
      )
      assert result == expected
      check_roundtrip(result, engine=engine, pretty=pretty)
  
imports: import pytest
  import plotly.io.json
  import plotly.graph_objects
  import plotly.express
  import numpy
  import pandas
  import json
  import datetime
  import re
  import sys
  import warnings
  from pytz import timezone
  from _plotly_utils.optional_imports import get_module
label_desc: Use image node_id 19 for calling a global function with example usage: test_datetime(datetime_value, engine, pretty) without return types