code: def __loadMedPriceDS(self):
      ret = dataseries.SequenceDataSeries()
      for i in xrange(len(OPEN_VALUES)):
          ret.append(
              LOW_VALUES[i] + (HIGH_VALUES[i] - LOW_VALUES[i]) / 2.0
          )
      return ret
  
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 1 for calling the TestCase obj's underlying member method code with example usage: obj.__loadMedPriceDS() and returns: ret