code: def test_eventplot(self):
      mpl.rcParams["date.converter"] = "concise"
  
      fig, (ax1, ax2, ax3) = plt.subplots(3, 1, layout="constrained")
  
      x_dates1 = np.array(
          [
              datetime.datetime(2020, 6, 30),
              datetime.datetime(2020, 7, 22),
              datetime.datetime(2020, 8, 3),
              datetime.datetime(2020, 9, 14),
          ],
          dtype=np.datetime64,
      )
  
      ax1.eventplot(x_dates1)
  
      np.random.seed(19680801)
  
      start_date = datetime.datetime(2020, 7, 1)
      end_date = datetime.datetime(2020, 10, 15)
      date_range = end_date - start_date
  
      dates1 = start_date + np.random.rand(30) * date_range
      dates2 = start_date + np.random.rand(10) * date_range
      dates3 = start_date + np.random.rand(50) * date_range
  
      colors1 = ["C1", "C2", "C3"]
      lineoffsets1 = np.array([1, 6, 8])
      linelengths1 = [5, 2, 3]
  
      ax2.eventplot(
          [dates1, dates2, dates3],
          colors=colors1,
          lineoffsets=lineoffsets1,
          linelengths=linelengths1,
      )
  
      lineoffsets2 = np.array(
          [
              datetime.datetime(2020, 7, 1),
              datetime.datetime(2020, 7, 15),
              datetime.datetime(2020, 8, 1),
          ],
          dtype=np.datetime64,
      )
  
      ax3.eventplot(
          [dates1, dates2, dates3],
          colors=colors1,
          lineoffsets=lineoffsets2,
          linelengths=linelengths1,
      )
  
imports: import datetime
  import numpy
  import pytest
  import matplotlib.pyplot
  import matplotlib
label_desc: Use image node_id 19 for calling the TestDatetimePlotting obj's underlying member method code with example usage: obj.test_eventplot() without return types