code: def testDateTimes(self):
      ds = bards.BarDataSeries()
      firstDt = datetime.datetime.now()
      for i in xrange(10):
          ds.append(
              bar.BasicBar(
                  firstDt + datetime.timedelta(seconds=i),
                  2,
                  4,
                  1,
                  3,
                  10,
                  3,
                  bar.Frequency.SECOND,
              )
          )
  
      for i in xrange(10):
          self.assertEqual(ds[i].getDateTime(), ds.getDateTimes()[i])
          self.assertEqual(
              ds.getDateTimes()[i],
              firstDt + datetime.timedelta(seconds=i),
          )
  
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 7 for calling the TestBarDataSeries obj's underlying member method code with example usage: obj.testDateTimes() without return types