code: def testNonEmpty(self):
      ds = bards.BarDataSeries()
      for i in xrange(10):
          ds.append(
              bar.BasicBar(
                  datetime.datetime.now()
                  + datetime.timedelta(seconds=i),
                  0,
                  0,
                  0,
                  0,
                  0,
                  0,
                  bar.Frequency.SECOND,
              )
          )
  
      for i in xrange(0, 10):
          self.assertTrue(ds[i].getOpen() == 0)
  
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 3 for calling the TestBarDataSeries obj's underlying member method code with example usage: obj.testNonEmpty() without return types