code: def test_numpy_dates(self):
      a = np.arange(
          np.datetime64("2011-07-11"), np.datetime64("2011-07-18")
      )
      j1 = _json.dumps(a, cls=utils.PlotlyJSONEncoder)
      assert (
          j1 == '["2011-07-11", "2011-07-12", "2011-07-13", '
          '"2011-07-14", "2011-07-15", "2011-07-16", '
          '"2011-07-17"]'
      )
  
imports: import datetime
  import math
  import decimal
  from datetime import datetime
  from unittest import TestCase
  from time import time
  import pytest
  import numpy
  import pandas
  import pytz
  from pandas.testing import assert_series_equal
  import json
  import os
  import base64
  from plotly import optional_imports, utils
  import plotly.graph_objects
  from plotly.graph_objs import Scatter, Scatter3d, Figure, Data
  from plotly.utils import get_by_path
  from PIL import Image
label_desc: Use image node_id 17 for calling the TestJSONEncoder obj's underlying member method code with example usage: obj.test_numpy_dates() without return types