code: def test_hlines(self):
      mpl.rcParams["date.converter"] = "concise"
      fig, axs = plt.subplots(2, 4, layout="constrained")
      dateStrs = [
          "2023-03-08",
          "2023-04-09",
          "2023-05-13",
          "2023-07-28",
          "2023-12-24",
      ]
      dates = [datetime.datetime(2023, m * 2, 10) for m in range(1, 6)]
      date_start = [
          datetime.datetime(2023, 6, d) for d in range(5, 30, 5)
      ]
      date_end = [
          datetime.datetime(2023, 7, d) for d in range(5, 30, 5)
      ]
      npDates = [np.datetime64(s) for s in dateStrs]
      axs[0, 0].hlines(
          y=dates,
          xmin=[0.1, 0.2, 0.3, 0.4, 0.5],
          xmax=[0.5, 0.6, 0.7, 0.8, 0.9],
      )
      axs[0, 1].hlines(
          dates,
          xmin=datetime.datetime(2020, 5, 10),
          xmax=datetime.datetime(2020, 5, 31),
      )
      axs[0, 2].hlines(dates, xmin=date_start, xmax=date_end)
      axs[0, 3].hlines(dates, xmin=0.45, xmax=0.65)
      axs[1, 0].hlines(
          y=npDates,
          xmin=[0.5, 0.6, 0.7, 0.8, 0.9],
          xmax=[0.1, 0.2, 0.3, 0.4, 0.5],
      )
      axs[1, 2].hlines(y=npDates, xmin=date_start, xmax=date_end)
      axs[1, 1].hlines(
          npDates,
          xmin=datetime.datetime(2020, 5, 10),
          xmax=datetime.datetime(2020, 5, 31),
      )
      axs[1, 3].hlines(npDates, xmin=0.45, xmax=0.65)
  
imports: import datetime
  import numpy
  import pytest
  import matplotlib.pyplot
  import matplotlib
label_desc: Use image node_id 26 for calling the TestDatetimePlotting obj's underlying member method code with example usage: obj.test_hlines() without return types