code: def test_imshow(self):
      fig, ax = plt.subplots()
      a = np.diag(range(5))
      dt_start = datetime.datetime(2010, 11, 1)
      dt_end = datetime.datetime(2010, 11, 11)
      extent = (dt_start, dt_end, dt_start, dt_end)
      ax.imshow(a, extent=extent)
      ax.tick_params(axis="x", labelrotation=90)
  
imports: import datetime
  import numpy
  import pytest
  import matplotlib.pyplot
  import matplotlib
label_desc: Use image node_id 27 for calling the TestDatetimePlotting obj's underlying member method code with example usage: obj.test_imshow() without return types