code: def testBETA(self):
      barDs = self.__loadBarDS()
      self.assertAmountsAreEqual(
          indicator.BETA(
              barDs.getHighDataSeries(),
              barDs.getLowDataSeries(),
              252,
              5,
          )[5],
          0.62907,
      )
      self.assertAmountsAreEqual(
          indicator.BETA(
              barDs.getHighDataSeries(),
              barDs.getLowDataSeries(),
              252,
              5,
          )[6],
          0.83604,
      )
  
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 15 for calling the TestCase obj's underlying member method code with example usage: obj.testBETA() without return types