code: def testSeqLikeOps(self):
      seq = []
      ds = bards.BarDataSeries()
      for i in xrange(10):
          bar_ = bar.BasicBar(
              datetime.datetime.now() + datetime.timedelta(seconds=i),
              2,
              4,
              1,
              3,
              10,
              3,
              bar.Frequency.SECOND,
          )
          ds.append(bar_)
          seq.append(bar_)
  
      self.assertEqual(ds[-1], seq[-1])
      self.assertEqual(ds[-2], seq[-2])
      self.assertEqual(ds[0], seq[0])
      self.assertEqual(ds[1], seq[1])
      self.assertEqual(ds[-2:][-1], seq[-2:][-1])
  
imports: import datetime
  from six.moves import xrange
  from .None import common
  from pyalgotrade import dataseries
  from pyalgotrade.dataseries import bards
  from pyalgotrade.dataseries import aligned
  from pyalgotrade import bar
label_desc: Use image node_id 6 for calling the TestBarDataSeries obj's underlying member method code with example usage: obj.testSeqLikeOps() without return types