code: def testCORREL(self):
      barDs = self.__loadBarDS()
      self.assertAmountsAreEqual(
          indicator.CORREL(
              barDs.getHighDataSeries(),
              barDs.getLowDataSeries(),
              252,
              20,
          )[19],
          0.9401569,
      )
      self.assertAmountsAreEqual(
          indicator.CORREL(
              barDs.getHighDataSeries(),
              barDs.getLowDataSeries(),
              252,
              20,
          )[20],
          0.9471812,
      )
      self.assertAmountsAreEqual(
          indicator.CORREL(
              barDs.getHighDataSeries(),
              barDs.getLowDataSeries(),
              252,
              20,
          )[-1],
          0.8866901,
      )
  
imports: import datetime
  import talib
  from six.moves import xrange
  from .None import common
  from pyalgotrade.talibext import indicator
  from pyalgotrade import bar
  from pyalgotrade import dataseries
  from pyalgotrade.dataseries import bards
label_desc: Use image node_id 19 for calling the TestCase obj's underlying member method code with example usage: obj.testCORREL() without return types