code: def testShortPeriod(self):
      highPrices = [3, 3, 3]
      lowPrices = [1, 1, 1]
      closePrices = [2, 2, 3]
  
      barDS = bards.BarDataSeries()
      stochFilter = stoch.StochasticOscillator(barDS, 2, 2)
      self.__fillBarDataSeries(
          barDS, closePrices, highPrices, lowPrices
      )
  
      self.assertTrue(values_equal(stochFilter[0], None))
      self.assertTrue(values_equal(stochFilter[1], 50))
      self.assertTrue(values_equal(stochFilter[2], 100))
  
      self.assertTrue(values_equal(stochFilter.getD()[0], None))
      self.assertTrue(values_equal(stochFilter.getD()[1], None))
      self.assertTrue(values_equal(stochFilter.getD()[2], 75))
  
      self.assertEqual(
          len(stochFilter.getDateTimes()), len(closePrices)
      )
      for i in range(len(stochFilter)):
          self.assertNotEqual(stochFilter.getDateTimes()[i], None)
  
file_path: pyalgotrade/testcases/technical_stoch_test.py
imports: import datetime
  from six.moves import xrange
  from .None import common
  from pyalgotrade.technical import stoch
  from pyalgotrade.dataseries import bards
  from pyalgotrade import bar
label_desc: Use image node_id 4 for calling the TestCase obj's underlying member method code with example usage: obj.testShortPeriod() without return types